Cpap system

ABSTRACT

An apparatus for humidifying a flow of breathable gas includes a water reservoir and a water reservoir dock forming a cavity structured and arranged to receive the water reservoir in an operative position. The water reservoir comprises a reservoir base including a cavity structured to hold a volume of water, the reservoir base including a main body and a thermally conductive portion provided to the main body. The thermally conductive portion comprises a combined layered arrangement including a metal plate and a thin film, the thin film comprising a non-metallic material and including a wall thickness of less than about 1 mm. The thin film is adapted to form at least a bottom interior surface of the water reservoir exposed to the volume of water, and the metal plate is adapted to form a bottom exterior surface of the water reservoir.

1 CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/295,160, filed May 19, 2021, which is the U.S. national phase ofInternational Application No. PCT/IB2020/053608, filed Apr. 16, 2020,which designated the U.S. and claims priority to U.S. ProvisionalApplication No. 62/835,094, filed Apr. 17, 2019, and U.S. ProvisionalApplication No. 62/897,558, filed Sep. 9, 2019, the entire contents ofeach of which are hereby incorporated by reference.

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in Patent Office patent files orrecords, but otherwise reserves all copyright rights whatsoever.

2 BACKGROUND OF THE TECHNOLOGY 2.1 Field of the Technology

The present technology relates to one or more of the screening,diagnosis, monitoring, treatment, prevention and amelioration ofrespiratory-related disorders. The present technology also relates tomedical devices or apparatus, and their use.

2.2 Description of the Related Art 2.2.1 Human Respiratory System andits Disorders

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include a series of branching tubes, which become narrower,shorter and more numerous as they penetrate deeper into the lung. Theprime function of the lung is gas exchange, allowing oxygen to move fromthe inhaled air into the venous blood and carbon dioxide to move in theopposite direction. The trachea divides into right and left mainbronchi, which further divide eventually into terminal bronchioles. Thebronchi make up the conducting airways, and do not take part in gasexchange. Further divisions of the airways lead to the respiratorybronchioles, and eventually to the alveoli. The alveolated region of thelung is where the gas exchange takes place, and is referred to as therespiratory zone. See “Respiratory Physiology”, by John B. West,Lippincott Williams & Wilkins, 9th edition published 2012.

A range of respiratory disorders exist. Certain disorders may becharacterised by particular events, e.g. apneas, hypopneas, andhyperpneas.

Examples of respiratory disorders include Obstructive Sleep Apnea (OSA),Cheyne-Stokes Respiration (CSR), respiratory insufficiency, ObesityHyperventilation Syndrome (OHS), Chronic Obstructive Pulmonary Disease(COPD), Neuromuscular Disease (NMD) and Chest wall disorders.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing(SDB), is characterised by events including occlusion or obstruction ofthe upper air passage during sleep. It results from a combination of anabnormally small upper airway and the normal loss of muscle tone in theregion of the tongue, soft palate and posterior oropharyngeal wallduring sleep. The condition causes the affected patient to stopbreathing for periods typically of 30 to 120 seconds in duration,sometimes 200 to 300 times per night. It often causes excessive daytimesomnolence, and it may cause cardiovascular disease and brain damage.The syndrome is a common disorder, particularly in middle agedoverweight males, although a person affected may have no awareness ofthe problem. See U.S. Pat. No. 4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is another form of sleep disorderedbreathing. CSR is a disorder of a patient's respiratory controller inwhich there are rhythmic alternating periods of waxing and waningventilation known as CSR cycles. CSR is characterised by repetitivede-oxygenation and re-oxygenation of the arterial blood. It is possiblethat CSR is harmful because of the repetitive hypoxia. In some patientsCSR is associated with repetitive arousal from sleep, which causessevere sleep disruption, increased sympathetic activity, and increasedafterload. See U.S. Pat. No. 6,532,959 (Berthon-Jones).

Respiratory failure is an umbrella term for respiratory disorders inwhich the lungs are unable to inspire sufficient oxygen or exhalesufficient CO₂ to meet the patient's needs. Respiratory failure mayencompass some or all of the following disorders.

A patient with respiratory insufficiency (a form of respiratory failure)may experience abnormal shortness of breath on exercise.

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

A range of therapies have been used to treat or ameliorate suchconditions. Furthermore, otherwise healthy individuals may takeadvantage of such therapies to prevent respiratory disorders fromarising. However, these have a number of shortcomings.

2.2.2 Therapy

Various therapies, such as Continuous Positive Airway Pressure (CPAP)therapy, Non-invasive ventilation (NIV) and Invasive ventilation (IV)have been used to treat one or more of the above respiratory disorders.

Continuous Positive Airway Pressure (CPAP) therapy has been used totreat Obstructive Sleep Apnea (OSA). The mechanism of action is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion, such as by pushing the soft palate andtongue forward and away from the posterior oropharyngeal wall. Treatmentof OSA by CPAP therapy may be voluntary, and hence patients may electnot to comply with therapy if they find devices used to provide suchtherapy one or more of: uncomfortable, difficult to use, expensive andaesthetically unappealing.

Non-invasive ventilation (NIV) provides ventilatory support to a patientthrough the upper airways to assist the patient breathing and/ormaintain adequate oxygen levels in the body by doing some or all of thework of breathing. The ventilatory support is provided via anon-invasive patient interface. NIV has been used to treat CSR andrespiratory failure, in forms such as OHS, COPD, NMD and Chest Walldisorders. In some forms, the comfort and effectiveness of thesetherapies may be improved.

Invasive ventilation (IV) provides ventilatory support to patients thatare no longer able to effectively breathe themselves and may be providedusing a tracheostomy tube. In some forms, the comfort and effectivenessof these therapies may be improved.

2.2.3 Treatment Systems

These therapies may be provided by a treatment system or device. Suchsystems and devices may also be used to screen, diagnose, or monitor acondition without treating it.

A treatment system may comprise a Respiratory Pressure Therapy Device(RPT device), an air circuit, a humidifier, a patient interface, anddata management.

Another form of treatment system is a mandibular repositioning device.

2.2.3.1 Patient Interface

A patient interface may be used to interface respiratory equipment toits wearer, for example by providing a flow of air to an entrance to theairways. The flow of air may be provided via a mask to the nose and/ormouth, a tube to the mouth or a tracheostomy tube to the trachea of apatient. Depending upon the therapy to be applied, the patient interfacemay form a seal, e.g., with a region of the patient's face, tofacilitate the delivery of gas at a pressure at sufficient variance withambient pressure to effect therapy, e.g., at a positive pressure ofabout 10 cmH₂O relative to ambient pressure. For other forms of therapy,such as the delivery of oxygen, the patient interface may not include aseal sufficient to facilitate delivery to the airways of a supply of gasat a positive pressure of about 10 cmH₂O.

Certain other mask systems may be functionally unsuitable for thepresent field. For example, purely ornamental masks may be unable tomaintain a suitable pressure. Mask systems used for underwater swimmingor diving may be configured to guard against ingress of water from anexternal higher pressure, but not to maintain air internally at a higherpressure than ambient.

Certain masks may be clinically unfavourable for the present technologye.g. if they block airflow via the nose and only allow it via the mouth.

Certain masks may be uncomfortable or impractical for the presenttechnology if they require a patient to insert a portion of a maskstructure in their mouth to create and maintain a seal via their lips.

Certain masks may be impractical for use while sleeping, e.g. forsleeping while lying on one's side in bed with a head on a pillow.

The design of a patient interface presents a number of challenges. Theface has a complex three-dimensional shape. The size and shape of nosesand heads varies considerably between individuals. Since the headincludes bone, cartilage and soft tissue, different regions of the facerespond differently to mechanical forces. The jaw or mandible may moverelative to other bones of the skull. The whole head may move during thecourse of a period of respiratory therapy.

As a consequence of these challenges, some masks suffer from being oneor more of obtrusive, aesthetically undesirable, costly, poorly fitting,difficult to use, and uncomfortable especially when worn for longperiods of time or when a patient is unfamiliar with a system. Wronglysized masks can give rise to reduced compliance, reduced comfort andpoorer patient outcomes. Masks designed solely for aviators, masksdesigned as part of personal protection equipment (e.g. filter masks),SCUBA masks, or for the administration of anaesthetics may be tolerablefor their original application, but nevertheless such masks may beundesirably uncomfortable to be worn for extended periods of time, e.g.,several hours. This discomfort may lead to a reduction in patientcompliance with therapy. This is even more so if the mask is to be wornduring sleep.

CPAP therapy is highly effective to treat certain respiratory disorders,provided patients comply with therapy. If a mask is uncomfortable, ordifficult to use a patient may not comply with therapy. Since it isoften recommended that a patient regularly wash their mask, if a mask isdifficult to clean (e.g., difficult to assemble or disassemble),patients may not clean their mask and this may impact on patientcompliance.

While a mask for other applications (e.g. aviators) may not be suitablefor use in treating sleep disordered breathing, a mask designed for usein treating sleep disordered breathing may be suitable for otherapplications.

For these reasons, patient interfaces for delivery of CPAP during sleepform a distinct field.

2.2.3.2 Respiratory Pressure Therapy (RPT) Device

A respiratory pressure therapy (RPT) device may be used individually oras part of a system to deliver one or more of a number of therapiesdescribed above, such as by operating the device to generate a flow ofair for delivery to an interface to the airways. The flow of air may bepressurised. Examples of RPT devices include a CPAP device and aventilator.

Air pressure generators are known in a range of applications, e.g.industrial-scale ventilation systems. However, air pressure generatorsfor medical applications have particular requirements not fulfilled bymore generalised air pressure generators, such as the reliability, sizeand weight requirements of medical devices. In addition, even devicesdesigned for medical treatment may suffer from shortcomings, pertainingto one or more of: comfort, noise, ease of use, efficacy, size, weight,manufacturability, cost, and reliability.

An example of the special requirements of certain RPT devices isacoustic noise.

Table of noise output levels of prior RPT devices (one specimen only,measured using test method specified in ISO 3744 in CPAP mode at 10cmH₂O).

A-weighted sound pressure Year RPT Device name level dB(A) (approx.)C-Series Tango ™ 31.9 2007 C-Series Tango ™ with Humidifier 33.1 2007 S8Escape ™ II 30.5 2005 S8 Escape ™ II with H4i ™ Humidifier 31.1 2005 S9AutoSet ™ 26.5 2010 S9 AutoSet ™ with H5i Humidifier 28.6 2010

One known RPT device used for treating sleep disordered breathing is theS9 Sleep Therapy System, manufactured by ResMed Limited. Another exampleof an RPT device is a ventilator. Ventilators such as the ResMedStellar™ Series of Adult and Paediatric Ventilators may provide supportfor invasive and non-invasive non-dependent ventilation for a range ofpatients for treating a number of conditions such as but not limited toNMD, OHS and COPD.

The ResMed Elisée™ 150 ventilator and ResMed VS III™ ventilator mayprovide support for invasive and non-invasive dependent ventilationsuitable for adult or paediatric patients for treating a number ofconditions. These ventilators provide volumetric and barometricventilation modes with a single or double limb circuit. RPT devicestypically comprise a pressure generator, such as a motor-driven bloweror a compressed gas reservoir, and are configured to supply a flow ofair to the airway of a patient. In some cases, the flow of air may besupplied to the airway of the patient at positive pressure. The outletof the RPT device is connected via an air circuit to a patient interfacesuch as those described above.

The designer of a device may be presented with an infinite number ofchoices to make. Design criteria often conflict, meaning that certaindesign choices are far from routine or inevitable. Furthermore, thecomfort and efficacy of certain aspects may be highly sensitive tosmall, subtle changes in one or more parameters.

2.2.3.3 Humidifier

Delivery of a flow of air without humidification may cause drying ofairways. The use of a humidifier with an RPT device and the patientinterface produces humidified gas that minimizes drying of the nasalmucosa and increases patient airway comfort. In addition in coolerclimates, warm air applied generally to the face area in and about thepatient interface is more comfortable than cold air.

A range of artificial humidification devices and systems are known,however they may not fulfil the specialised requirements of a medicalhumidifier.

Medical humidifiers are used to increase humidity and/or temperature ofthe flow of air in relation to ambient air when required, typicallywhere the patient may be asleep or resting (e.g. at a hospital). Amedical humidifier for bedside placement may be small. A medicalhumidifier may be configured to only humidify and/or heat the flow ofair delivered to the patient without humidifying and/or heating thepatient's surroundings. Room-based systems (e.g. a sauna, an airconditioner, or an evaporative cooler), for example, may also humidifyair that is breathed in by the patient, however those systems would alsohumidify and/or heat the entire room, which may cause discomfort to theoccupants. Furthermore medical humidifiers may have more stringentsafety constraints than industrial humidifiers.

While a number of medical humidifiers are known, they can suffer fromone or more shortcomings. Some medical humidifiers may provideinadequate humidification, some are difficult or inconvenient to use bypatients.

2.2.3.4 Data Management

There may be clinical reasons to obtain data to determine whether thepatient prescribed with respiratory therapy has been “compliant”, e.g.that the patient has used their RPT device according to one or more“compliance rules”. One example of a compliance rule for CPAP therapy isthat a patient, in order to be deemed compliant, is required to use theRPT device for at least four hours a night for at least 21 of 30consecutive days. In order to determine a patient's compliance, aprovider of the RPT device, such as a health care provider, may manuallyobtain data describing the patient's therapy using the RPT device,calculate the usage over a predetermined time period, and compare withthe compliance rule. Once the health care provider has determined thatthe patient has used their RPT device according to the compliance rule,the health care provider may notify a third party that the patient iscompliant.

There may be other aspects of a patient's therapy that would benefitfrom communication of therapy data to a third party or external system.

Existing processes to communicate and manage such data can be one ormore of costly, time-consuming, and error-prone.

3 BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the screening, diagnosis, monitoring, amelioration, treatment,or prevention of respiratory disorders having one or more of improvedcomfort, cost, efficacy, ease of use and manufacturability.

A first aspect of the present technology relates to apparatus used inthe screening, diagnosis, monitoring, amelioration, treatment orprevention of a respiratory disorder.

Another aspect of the present technology relates to methods used in thescreening, diagnosis, monitoring, amelioration, treatment or preventionof a respiratory disorder.

An aspect of certain forms of the present technology is to providemethods and/or apparatus that improve the compliance of patients withrespiratory therapy.

An aspect of one form of the present technology is a method ofmanufacturing apparatus.

An aspect of certain forms of the present technology is a medical devicethat is easy to use, e.g. by a person who does not have medicaltraining, by a person who has limited dexterity, vision or by a personwith limited experience in using this type of medical device.

An aspect of one form of the present technology is a portable RPT devicethat may be carried by a person, e.g., around the home of the person.

An aspect of one form of the present technology is a patient interfacethat may be washed in a home of a patient, e.g., in soapy water, withoutrequiring specialised cleaning equipment. An aspect of one form of thepresent technology is a humidifier tank that may be washed in a home ofa patient, e.g., in soapy water, without requiring specialised cleaningequipment.

An aspect of one form of the present technology relates to respiratorytreatment apparatus including a source of a flow of air at positivepressure, a chassis or housing constructed and arranged to be fixed inlocation in use relative to the source, an inlet pneumatic connectionstructured for connecting to the source to receive sealably the flow ofair at positive pressure from the source in use, a container to hold abody of water in use, the container being configured to direct the flowof air so that water vapour may transfer from the body of water to theflow of air in use to increase the absolute humidity of the flow of air,the container including a wall constructed at least in part from amaterial having a relatively high thermal conductivity, a heatingelement, a temperature sensor, a controller to control the heatingelement, and an outlet pneumatic connection structure to receive theflow of air with increased absolute humidity. The chassis or housing isconfigured to hold the container in location close relative to theheating element so that heat energy may transfer from the heatingelement to the body of water to increase the absolute humidity of theflow of air. The controller is constructed and arranged to cause theenergising of the heating element to heat the water without boiling thewater. The respiratory treatment apparatus includes a sealingarrangement so that in use the flow of air with increased absolutehumidity received at the outlet pneumatic connection structure has apositive pressure with respect to ambient.

Another aspect of the present technology relates to a CPAP systemincluding a humidifier, a patient interface, and an air delivery tube todeliver humidified air to the patient interface. In an example, thehumidifier is integrated with an RPT device structured to produce a flowof air at positive pressure.

Another aspect of the present technology relates to a humidifierincluding a water reservoir including a cavity structured to hold avolume of water, and a water reservoir dock structured and arranged toreceive the water reservoir in an operative position.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir and a water reservoir dock forming a cavity structured andarranged to receive the water reservoir in an operative position. Thewater reservoir includes a reservoir base including a cavity structuredto hold a volume of water. The reservoir base includes a main body and athermally conductive portion provided to the main body. The thermallyconductive portion comprises a combined layered arrangement including ametal plate and a thin film. The thin film comprises a non-metallicmaterial and includes a wall thickness of less than about 1 mm. The thinfilm is adapted to form at least a bottom interior surface of the waterreservoir exposed to the volume of water, and the metal plate is adaptedto form a bottom exterior surface of the water reservoir. The waterreservoir dock includes a heater plate adapted to thermally contact themetal plate of the water reservoir in the operative position to allowthermal transfer of heat from the heater plate to the volume of water.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, awater reservoir dock structured and arranged to receive the waterreservoir in an operative position, and a guide arrangement structuredand arranged to guide the water reservoir into and out of the operativeposition. The water reservoir includes a conductive portion, and thewater reservoir dock includes a heating assembly adapted to thermallyengage the conductive portion of the water reservoir in the operativeposition to allow thermal transfer of heat from the heating assembly tothe volume of water. The guide arrangement includes a path extendingboth in an anterior-posterior direction and in an inferior-superiordirection.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, awater reservoir dock structured and arranged to receive the waterreservoir in an operative position, and an air delivery tube configuredto pass the flow of breathable gas that has been humidified in the waterreservoir to a patient interface. The air delivery tube is structuredand arranged to form a direct pneumatic seal with the water reservoir.

Another aspect of the present technology relates to a water reservoirincluding an inlet tube providing an inlet for receiving a flow ofbreathable gas and an outlet tube providing an outlet for delivering ahumidified flow of breathable gas, wherein the inlet tube includes aninlet seal and the outlet tube includes an outlet seal.

Another aspect of the present technology relates to a water reservoirfor an apparatus for humidifying a flow of breathable gas. The waterreservoir includes an inlet tube arranged to provide an inlet forreceiving a flow of breathable gas into the water reservoir and anoutlet tube arranged to provide an outlet for delivering a flow ofhumidified breathable gas from the water reservoir. At least one of theinlet tube and the outlet tube changes a parameter at least at one pointalong its length. For example, at least one of the inlet tube and theoutlet tube may change direction and/or cross-sectional area at least atone point along its length. In a more specific example, the inlet tube,the outlet tube, or both may curve along its/their length and/or changeits cross-section along its length. The change may be abrupt (stepwise)or gradual.

Another aspect of the present technology relates to a water reservoirincluding a conductive portion adapted to thermally engage with aheating assembly, wherein the conductive portion includes a firstportion that extends in a first plane and a second portion that extendsin a second plane that is offset in a superior direction from the firstplane.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir, a water reservoir dock structured and arranged to receive thewater reservoir, and an air delivery tube, wherein insertion/removal ofthe water reservoir to/from the water reservoir dock is independent fromengagement/disengagement of the air delivery tube to/from the waterreservoir dock.

Another aspect of the present technology relates to a heating assemblyfor a water reservoir dock including a heater plate, a heating element,and a thermal pad arranged between the heater plate and the heatingelement, e.g., to enhance thermal conductivity from the heating elementto the heater plate.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, thewater reservoir including a conductive portion, and a water reservoirdock structured and arranged to receive the water reservoir in anoperative position, the water reservoir dock including a heatingassembly adapted to thermally engage the conductive portion of the waterreservoir in the operative position to allow thermal transfer of heatfrom the heating assembly to the volume of water. The heating assemblyincludes a heater plate to thermally contact the conductive portion ofthe water reservoir, a heating element, and a thermal pad arrangedbetween the heater plate and the heating element. The thermal padcomprises a pliable material structured and arranged to engage both theheater plate and the heating element to remove air gaps and spacesbetween the heater plate and the heating element to enhance thermalconductivity.

Another aspect of the present technology relates to a water reservoirincluding a conductive portion adapted to thermally engage with aheating assembly, wherein the conductive portion includes one of a metalplate, a thin, non-metallic film, or a combined layered arrangement of ametal plate and a thin, non-metallic film. In an example, the conductiveportion may include circular or non-circular shapes.

Another aspect of the present technology relates to including one ormore circuit components in an air delivery tube for identifying a typeof air delivery tube based on characteristics of the circuit components.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, awater reservoir dock structured and arranged to receive the waterreservoir in an operative position, and an air delivery tube configuredto pass the flow of breathable gas that has been humidified in the waterreservoir to a patient interface. The air delivery tube includes a dockconnector including a contact assembly. The contact assembly includeselectrical contacts adapted to, in an operative configuration of theapparatus, engage respective electrical contacts provided to the waterreservoir dock. The contact assembly includes an electricalcharacteristic used as an identifier of one or more parameters of theair delivery tube or the patient interface.

Another aspect of the present technology relates to processing circuitryconfigured to identify a type of air delivery tube coupled to anapparatus for humidifying a flow of breathable gas based on measuredcharacteristics of a passive circuit component in the air delivery tube.

Another aspect of the present technology relates to processing circuitryconfigured to identify a type of air delivery tube coupled to anapparatus for humidifying a flow of breathable gas based on measuringcharacteristics of circuitry in the air delivery tube. Thecharacteristics of the circuitry include a resistance value of one ormore heating elements in the air delivery tube and/or a resistance valueof one or more sensors in the air delivery tube.

Another aspect of the present technology relates to processing circuitryconfigured to identify a type of air delivery tube coupled to anapparatus for humidifying a flow of breathable gas based on resistancevalue of a first resistor and a resistance value of a second resistorprovided in the air delivery tube. The first resistor being coupled to afirst pair of contacts in the air delivery tube and the second resistorbeing coupled to a second pair of contacts in the air delivery tube.

Another aspect of the present technology relates to including one ormore filters coupled to a sensor circuit at least partially disposed inan air delivery tube for sensing temperature changes in the air deliverytube.

Another aspect of the present technology relates to including low passfilters coupled to a sensor circuit at least partially disposed in anair delivery tube for sensing temperature changes in the air deliverytube. The filters may be configured to filter pulse frequencies of thePWM signal applied to one or more heating elements in the air deliverytube.

Another aspect of the present technology relates to including one ormore low pass filters coupled to a sensor circuit at least partiallydisposed in an air delivery tube for sensing temperature changes in theair delivery tube, wherein a sensing signal is applied periodically tothe sensor circuit.

Another aspect of the present technology relates to including a firstlow pass filter coupled to one end of a sensor included in an airdelivery tube and a second low pass filter coupled to a second end ofthe sensor, wherein a sensing signal is applied at predeterminedintervals to the sensor for sensing temperature changes in the airdelivery tube.

Another aspect of the present technology relates to including a firstlow pass filter coupled to a first output of a divider network fordetecting operating parameters of a sensor disposed in an air deliverytube and a second low pass filter coupled to a second output of thedivider network.

Another aspect of the present technology relates to an apparatus forproviding a supply of humidified pressurized breathable gas to a patientinterface. The apparatus includes a flow generator configured topressurize a supply of breathable gas, a humidifier configured toprovide water vapour to humidify the supply of pressurized breathablegas, a heated tube configured to be connectable to the humidifier toheat and deliver the humidified supply of breathable gas to the patientinterface, a sensor configured to measure a property of the humidifiedsupply of breathable gas in the heated tube, a controller configured tocontrol power provided to the heated tube and control operation of theflow generator, and a set of low pass filters coupled between the sensorand the controller and/or a set of low pass filters coupled between thesensor and ground.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas including a water reservoirincluding a cavity structured to hold a volume of water, a waterreservoir dock structured and arranged to receive the water reservoir inan operative position, an air delivery tube configured to pass the flowof breathable gas that has been humidified in the water reservoir to apatient interface, and an intermediate component removably andnon-rotatably coupled to the water reservoir dock. The intermediatecomponent is configured to pneumatically connect the water reservoir tothe air delivery tube. The intermediate component comprises a one-piececonstruction of a relatively rigid material including an inlet endadapted to interface with the water reservoir and an outlet end adaptedto interface with the air delivery tube. The air delivery tube includesa dock connector structured and arranged to form a bayonet-styleconnection with the water reservoir dock which mechanically andelectrically connects the air delivery tube with the water reservoirdock.

Another aspect of the present technology relates to a water reservoirfor humidifying a flow of breathable gas including a reservoir base, areservoir lid, and a hinge joint to hingedly couple the reservoir lid tothe reservoir base for hinged movement between an open position and aclosed position. The hinge joint includes a pair of hinge pins eachconfigured to engage with a respective one of a pair of slots to providesaid hinged movement. Each of the pair of hinge pins comprises across-section that represents a major segment of a circle.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, awater reservoir dock structured and arranged to receive the waterreservoir in an operative position, and a guide arrangement structuredand arranged to guide the water reservoir into the operative positionwith the water reservoir dock. The water reservoir includes a heatconductive portion. The water reservoir dock includes a heating assemblyadapted to thermally engage the heat conductive portion of the waterreservoir in the operative position to allow thermal transfer of heatfrom the heating assembly to the volume of water. The guide arrangementincludes a guiding rail on each side of the water reservoir and a guideslot on each side of the water reservoir dock, each guiding railconfigured to engage with a respective guide slot. The guide arrangementfurther includes one or more biasing edges or tabs provided to a leadingedge of the water reservoir configured to engage underneath a respectiveabutment edge provided to the water reservoir dock when the waterreservoir reaches the operative position. The engagement both biases thefront of the water reservoir downwardly and locks/prevents its movementin an upward direction.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water and awater reservoir dock structured and arranged to receive the waterreservoir in an operative position. The water reservoir includes a heatconductive portion, and the water reservoir dock includes a heatingassembly adapted to thermally engage the heat conductive portion of thewater reservoir in the operative position to allow thermal transfer ofheat from the heating assembly to the volume of water. The heatingassembly comprises a heater plate including a base surface to thermallycontact the heat conductive portion of the water reservoir and aresilient sealing and/or supporting member to resiliently suspend theheater plate within the water reservoir dock. The resilient sealingand/or supporting member comprises one or more hollow tubes, each of oneor more hollow tubes including an axis that is generally perpendicularto the base surface of the heater plate.

Another aspect of the present technology relates to an apparatus forhumidifying a flow of breathable gas. The apparatus includes a waterreservoir including a cavity structured to hold a volume of water, awater reservoir dock structured and arranged to receive the waterreservoir in an operative position, an air delivery tube configured topass the flow of breathable gas that has been humidified in the waterreservoir to a patient interface, and an intermediate component arrangedfor removably and non-rotatably coupling to the water reservoir dock andthe air delivery tube. The intermediate component is configured to, inan operational configuration, pneumatically connect the air deliverytube to the water reservoir.

Another aspect of the present technology relates to a water reservoirfor humidifying a flow of breathable gas including a reservoir baseincluding a cavity structured to hold a volume of water. The reservoirbase includes a main body and a thermally conductive portion provided tothe main body. The thermally conductive portion may comprise a thinfilm. The thin film comprises a non-metallic material and includes awall thickness of less than about 1 mm. The main body comprises aplastic material, and the thin film comprises a non-final form thatforms an insert molded connection with the main body. The thin film isformed in its final form (e.g. by stamping, vacuum forming or thermalvacuum forming) after it has been insert molded in the main body.

The methods, systems, devices and apparatus described may be implementedso as to improve the functionality of a processor, such as a processorof a specific purpose computer, respiratory monitor and/or a respiratorytherapy apparatus. Moreover, the described methods, systems, devices andapparatus can provide improvements in the technological field ofautomated management, monitoring and/or treatment of respiratoryconditions, including, for example, sleep disordered breathing.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

4 BRIEF DESCRIPTION OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

4.1 Treatment Systems

FIG. 1A shows a system including a patient 1000 wearing a patientinterface 3000, in the form of nasal pillows, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device4000 is humidified in a humidifier 5000, and passes along an air circuit4170 to the patient 1000. A bed partner 1100 is also shown. The patientis sleeping in a supine sleeping position.

FIG. 1B shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a nasal mask, receiving a supply of airat positive pressure from an RPT device 4000. Air from the RPT device ishumidified in a humidifier 5000, and passes along an air circuit 4170 tothe patient 1000.

FIG. 1C shows a system including a patient 1000 wearing a patientinterface 3000, in the form of a full-face mask, receiving a supply ofair at positive pressure from an RPT device 4000. Air from the RPTdevice is humidified in a humidifier 5000, and passes along an aircircuit 4170 to the patient 1000. The patient is sleeping in a sidesleeping position.

4.2 Respiratory System and Facial Anatomy

FIG. 2A shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2B shows a view of a human upper airway including the nasal cavity,nasal bone, lateral nasal cartilage, greater alar cartilage, nostril,lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

4.3 Patient Interface

FIG. 3A shows a patient interface in the form of a nasal mask inaccordance with one form of the present technology.

FIG. 3B shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3C.

FIG. 3C shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a positive sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3B.

FIG. 3D shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a value of zero.

FIG. 3E shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively small magnitude whencompared to the magnitude of the curvature shown in FIG. 3F.

FIG. 3F shows a schematic of a cross-section through a structure at apoint. An outward normal at the point is indicated. The curvature at thepoint has a negative sign, and a relatively large magnitude whencompared to the magnitude of the curvature shown in FIG. 3E.

FIG. 3G shows the surface of a structure, with a one dimensional hole inthe surface. The illustrated plane curve forms the boundary of a onedimensional hole.

FIG. 3H shows a cross-section through the structure of FIG. 3G. Theillustrated surface bounds a two dimensional hole in the structure ofFIG. 3G.

FIG. 3I shows a perspective view of the structure of FIG. 3G, includingthe two dimensional hole and the one dimensional hole. Also shown is thesurface that bounds a two dimensional hole in the structure of FIG. 3G.

4.4 Breathing Waveforms

FIG. 4 shows a model typical breath waveform of a person while sleeping.

4.5 RPT Device and Humidifier

FIG. 5A shows an exploded perspective view of an RPT device 4000 inaccordance with one form of the present technology.

FIG. 5B shows a perspective view of an RPT device 4000 comprising anoutlet cap with a muffler 4124 in accordance with one form of thepresent technology.

FIG. 5C shows a perspective view of an RPT device 4000 with anintegrated humidifier 5000 comprising a water reservoir 5110 inaccordance with one form of the present technology.

FIG. 5D is a schematic diagram of the pneumatic path of an RPT device inaccordance with one form of the present technology. The directions ofupstream and downstream are indicated with reference to the blower andthe patient interface. The blower is defined to be upstream of thepatient interface and the patient interface is defined to be downstreamof the blower, regardless of the actual flow direction at any particularmoment. Items which are located within the pneumatic path between theblower and the patient interface are downstream of the blower andupstream of the patient interface.

FIG. 5E is a schematic diagram of the electrical components of an RPTdevice in accordance with one form of the present technology.

FIG. 5F is a schematic diagram of the algorithms implemented in an RPTdevice in accordance with one form of the present technology.

FIG. 5G shows a schematic of a humidifier in accordance with one form ofthe present technology.

FIG. 6A is a perspective view of an integrated RPT device and humidifiercomprising a water reservoir according to an example of the presenttechnology.

FIG. 6B is a perspective view of the integrated RPT device andhumidifier of FIG. 6A with the water reservoir removed from thereservoir dock.

FIG. 7 is a perspective view of a pneumatic block according to anexample of the present technology.

FIG. 8A is a side view of the integrated RPT device and humidifier ofFIG. 6A according to an example of the present technology.

FIG. 8B is a cross-sectional view of the integrated RPT device andhumidifier of FIG. 8A, taken along line 8B-8B of FIG. 8A.

FIG. 8C is a front view of the cross-sectional view shown in FIG. 8B.

FIG. 8D is a cross-sectional view of the integrated RPT device andhumidifier of FIG. 8A, taken along line 8D-8D of FIG. 8A.

FIG. 9 is an exploded view of a water reservoir including a circularmetal plate according to an example of the present technology.

FIG. 10A is a top perspective view of a reservoir base of a humidifierreservoir including a rectangular metal plate according to an example ofpresent technology.

FIG. 10B is a bottom perspective view of the reservoir base of FIG. 10A.

FIG. 10C is a top view of the reservoir base of FIG. 10A.

FIG. 10D is a side view of the reservoir base of FIG. 10A.

FIG. 10E is a bottom view of the reservoir base of FIG. 10A.

FIG. 10F is a cross-sectional view of the reservoir base taken alongline 10F-10F of FIG. 10C according to an example of present technology.

FIG. 10G is an enlarged view of a portion of the reservoir base of FIG.10F.

FIG. 11A is a top perspective view of a reservoir base of a humidifierreservoir including a circular metal plate according to an example ofpresent technology.

FIG. 11B is a cross-sectional view of the reservoir base taken alongling 11B-11B of FIG. 11A according to an example of present technology.

FIG. 11C is an enlarged view of a portion of the reservoir base of FIG.11B.

FIG. 12A is a top perspective view of a reservoir base of a humidifierreservoir including a deeper drawn rectangular metal plate according toan example of present technology.

FIG. 12B is a cross-sectional view of the reservoir base taken alongline 12B-12B of FIG. 12A according to an example of present technology.

FIG. 12C is an enlarged view of a portion of the reservoir base of FIG.12B.

FIG. 13A is a top perspective view of a reservoir base of a humidifierreservoir including a rectangular, thin non-metallic film according toan example of present technology.

FIG. 13B is a cross-sectional view of the reservoir base taken alongline 13B-13B of FIG. 13A according to an example of present technology.

FIG. 13C is an enlarged view of a portion of the reservoir base of FIG.13B.

FIG. 14A is a top perspective view of a reservoir base of a humidifierreservoir including a circular, thin non-metallic film according to anexample of present technology.

FIG. 14B is a cross-sectional view of the reservoir base taken alongline 14B-14B of FIG. 14A according to an example of present technology.

FIG. 14C is an enlarged view of a portion of the reservoir base of FIG.14B.

FIG. 15A is a top perspective view of a reservoir base of a humidifierreservoir including a combined layered arrangement of a rectangular,metal plate and thin non-metallic film according to an example ofpresent technology.

FIG. 15B is a cross-sectional view of the reservoir base taken alongline 15B-15B of FIG. 15A according to an example of present technology.

FIG. 15C is an enlarged view of a portion of the reservoir base of FIG.15B.

FIG. 16A is a top perspective view of a reservoir base of a humidifierreservoir including a combined layered arrangement of a circular, metalplate and thin non-metallic film according to an example of presenttechnology.

FIG. 16B is a cross-sectional view of the reservoir base taken alongline 16B-16B of FIG. 16A according to an example of present technology.

FIG. 16C is an enlarged view of a portion of the reservoir base of FIG.16B.

FIG. 17A is a top perspective view of a reservoir base of a humidifierreservoir including a combined layered arrangement of a deeper drawnrectangular, metal plate and thin non-metallic film according to anexample of present technology.

FIG. 17B is a cross-sectional view of the reservoir base taken alongline 17B-17B of FIG. 17A according to an example of present technology.

FIG. 17C is an enlarged view of a portion of the reservoir base of FIG.17B.

FIG. 18A is a perspective view of a water reservoir according to anexample of the present technology.

FIG. 18B is a top view of the water reservoir of FIG. 18A.

FIG. 19A is a top view of a water reservoir according to an example ofthe present technology.

FIG. 19B is a side view of the water reservoir of FIG. 19A.

FIG. 19C is a cross-sectional view of the water reservoir taken alongline 19C-19C of FIG. 19A showing an inlet tube and outlet tubearrangement according to an example of the present technology.

FIG. 19D is a cross-sectional view of the water reservoir taken alongline 19D-19D of FIG. 19B showing the inlet tube and outlet tubearrangement according to an example of the present technology.

FIG. 19E is a cross-sectional view of the water reservoir taken alongline 19E-19E of FIG. 19A showing the inlet tube and outlet tubearrangement according to an example of the present technology.

FIG. 19F is a cross-sectional view of the water reservoir taken alongline 19F-19F of FIG. 19A showing the inlet tube and outlet tubearrangement according to an example of the present technology.

FIG. 19G is a cross-sectional view of the water reservoir taken alongline 19G-19G of FIG. 19A showing the inlet tube and outlet tubearrangement according to an example of the present technology, the waterreservoir rotated by 180 degrees to show spillback protection providedby the inlet tube and outlet tube arrangement.

FIG. 19H-1 is a top perspective view of a removable outlet tubearrangement for a water reservoir according to an example of the presenttechnology.

FIG. 19H-2 is a bottom perspective view of the removable outlet tubearrangement of FIG. 19G-1.

FIG. 19I is a perspective view of a removable inlet tube and outlet tubearrangement for a water reservoir according to an example of the presenttechnology.

FIG. 20A is a perspective view showing a reservoir dock and an airdelivery tube according to an example of the present technology.

FIG. 20B is a cut-out perspective view showing a dock outlet of areservoir dock according to an example of the present technology.

FIG. 20C is a cut-out front view showing a dock outlet of a reservoirdock according to an example of the present technology.

FIG. 20D is a perspective view showing a reservoir dock and an airdelivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20E is another perspective view showing a reservoir dock and an airdelivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20F is another perspective view showing a reservoir dock and an airdelivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20G is a cross-sectional view along line 20G-20G of FIG. 20Fshowing a reservoir dock and an air delivery tube connected to the dockoutlet of the reservoir dock according to an example of the presenttechnology.

FIG. 20H is another perspective view showing a reservoir dock and an airdelivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20I is an enlarged perspective view showing a reservoir dock and anair delivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20J is a perspective view showing an air delivery tube and itselectrical connections to a contact assembly of the dock outlet of thereservoir dock according to an example of the present technology.

FIG. 20K is an enlarged cut-out perspective view showing a reservoirdock and an air delivery tube connected to the dock outlet of thereservoir dock according to an example of the present technology.

FIG. 20L is an enlarged cut-out perspective view showing a reservoirdock and an air delivery tube being disconnected from the dock outlet ofthe reservoir dock according to an example of the present technology.

FIG. 20M is a cross-sectional view showing a reservoir dock and an airdelivery tube connected to the dock outlet of the reservoir dockaccording to an example of the present technology.

FIG. 20N is an enlarged view of a portion of the reservoir dock and airdelivery tube of FIG. 20M.

FIG. 21 is a schematic view showing a reservoir dock with an airdelivery tube and a water reservoir connected to the reservoir dockaccording to an example of the present technology.

FIG. 22A is a perspective view showing an air delivery tube engaged witha water reservoir according to an example of the present technology.

FIG. 22B is another perspective view of the air delivery tube and waterreservoir of FIG. 22A.

FIG. 22C is a top view of the air delivery tube and water reservoir ofFIG. 22A.

FIG. 23A is a perspective view showing a dock connector of an airdelivery tube according to an example of the present technology.

FIG. 23B is a top view of the air delivery tube of FIG. 23A.

FIG. 24A is a perspective view showing a dock connector of an airdelivery tube according to another example of the present technology.

FIG. 24B is another perspective view of the air delivery tube of FIG.24A without the overmolded grip.

FIG. 25A is a perspective view of a reservoir dock (in a cut-awayrepresentation) and a water reservoir including guiding structuresaccording to an example of the present technology.

FIG. 25B is a perspective view of the reservoir dock and water reservoirof FIG. 25A showing the water reservoir being inserted into thereservoir dock.

FIG. 26A is side view of the reservoir dock and water reservoir of FIG.25A showing the water reservoir being inserted into the reservoir dock.

FIG. 26B is side view of the reservoir dock and water reservoir of FIG.25A showing the water reservoir inserted into the reservoir dock.

FIG. 27A is a cross-sectional view of the reservoir dock and waterreservoir of FIG. 25A showing the water reservoir being inserted intothe reservoir dock.

FIG. 27B is a cross-sectional view of the reservoir dock and waterreservoir of FIG. 25A showing the water reservoir inserted into thereservoir dock.

FIG. 28A is a perspective view showing a reservoir dock including arecessed heating element according to an example of the presenttechnology.

FIG. 28B is a perspective view showing a heating element of thereservoir dock of FIG. 28A according to an example of the presenttechnology.

FIG. 28C is an enlarged cross-sectional view showing the reservoir dockand recessed heating element of FIG. 28A.

FIG. 29 is a bottom perspective view of a water reservoir according toan example of the present technology.

FIG. 30 is side view of a reservoir dock and a water reservoir includingguiding structures according to another example of the presenttechnology, and showing the water reservoir being inserted into thereservoir dock.

FIG. 31 is side view of the reservoir dock and water reservoir of FIG.30A showing the water reservoir inserted into the reservoir dock.

FIG. 32A is a cross-sectional view of the reservoir dock and waterreservoir of FIG. 30 showing the water reservoir being inserted into thereservoir dock.

FIG. 32B is a cross-sectional view of the reservoir dock and waterreservoir of FIG. 30 showing the water reservoir inserted into thereservoir dock.

FIG. 33A is a cross-sectional view showing a latch for a water reservoiraccording to an example of the present technology.

FIG. 33B is a cross-sectional view showing the latch of FIG. 33A engagedwith a reservoir dock according to an example of the present technology.

FIG. 33C is another cross-sectional view showing the latch of FIG. 33A.

FIG. 33D is another cross-sectional view showing the latch of FIG. 33A.

FIG. 33E is a perspective view showing the latch of FIG. 33A.

FIG. 33F is another perspective view showing the latch of FIG. 33A.

FIG. 33G is a perspective view showing a recess in a water reservoir forreceiving a latch according to an example of the present technology.

FIG. 34A is a cross-sectional view showing a heating assembly for areservoir dock according to an example of the present technology.

FIG. 34B is an exploded view of the heating assembly of FIG. 34A.

FIG. 34C is another cross-sectional view of the heating assembly of FIG.34A.

FIG. 35A shows a dock and a tube schematic connection in accordance withone form of the present technology.

FIG. 35B shows a circuit diagram of the dock and tube connection inaccordance with one form of the present technology.

FIG. 36 shows a dock and a tube schematic connection in accordance withone form of the present technology.

FIG. 37 shows exemplary tube NTC sensor resistance variations overdifferent temperatures for a 100 k thermistor and a 10 k thermistor.

FIG. 38 shows a dock and a tube schematic connection in accordance withanother form of the present technology.

FIG. 39 shows a dock and a tube schematic connection in accordance withanother form of the present technology.

FIG. 40 shows a tube with a four wire circuit coupled to a dock inaccordance with one form of the present technology.

FIG. 41 shows an exemplary signal diagram of a PWM signal that may beapplied to the heating elements and portions of PWM induced signal thatmay be observed in the sensing circuit.

FIG. 42 shows an exemplary divider network including low pass filters inaccordance with one form of the present technology.

FIG. 43 is a perspective view showing a reservoir dock, an intermediatecomponent, and an air delivery tube according to an example of thepresent technology, the air delivery tube oriented for engagement withthe intermediate component and a locking and contact assembly providedto the reservoir dock.

FIG. 44 is a perspective view showing the reservoir dock and the airdelivery tube of FIG. 43, the air delivery tube engaged with the lockingand contact assembly provided to the reservoir dock in an unlocked,engaged position.

FIG. 45 is a perspective view showing the reservoir dock and the airdelivery tube of FIG. 43, the air delivery tube engaged with the lockingand contact assembly provided to the reservoir dock in a lockedposition.

FIG. 46 is a perspective view showing the reservoir dock, theintermediate component, and the air delivery tube of FIG. 43.

FIG. 47 is an exploded view showing the reservoir dock, the intermediatecomponent, the air delivery tube, and the locking and contact assemblyof the reservoir dock of FIG. 43.

FIG. 48 is another exploded view showing the reservoir dock, theintermediate component, the air delivery tube, and the locking andcontact assembly of the reservoir dock of FIG. 43.

FIG. 49 is an exploded view showing the reservoir dock and the lockingand contact assembly thereof, the intermediate component, and the airdelivery tube of FIG. 43.

FIG. 50 is an enlarged elevated front perspective view of the reservoirdock of FIG. 43.

FIG. 51 is an enlarged perspective view showing the locking and contactassembly provided to the reservoir dock of FIG. 43.

FIG. 52 is another enlarged perspective view showing the locking andcontact assembly provided to the reservoir dock of FIG. 43.

FIG. 53 is a rear perspective view showing an intermediate componentaccording to an example of the present technology.

FIG. 54 is a front view of the intermediate component of FIG. 53.

FIG. 55 is a top view of the intermediate component of FIG. 53.

FIG. 56 is an exploded view of the intermediate component of FIG. 53.

FIG. 57 is an enlarged front perspective view showing the locking andcontact assembly and the intermediate component for the reservoir dockof FIG. 43.

FIG. 58 is a front view of the locking and contact assembly and theintermediate component of FIG. 57.

FIG. 59 is a perspective view showing a locking and contact assembly fora reservoir dock according to an example of the present technology.

FIG. 60 is an exploded view of the locking and contact assembly of FIG.59.

FIG. 61 is another exploded view of the locking and contact assembly ofFIG. 59.

FIG. 62 is a perspective view of the locking and contact assembly ofFIG. 59 with the cover removed.

FIG. 63 is a front view of the locking and contact assembly of FIG. 59.

FIG. 64 is a perspective view of a dock connector for an air deliverytube according to an example of the present technology.

FIG. 65 is a front view of the dock connector of FIG. 64.

FIG. 66 is a cross-sectional view through line 66-66 of FIG. 65.

FIG. 67 is a cross-sectional view through line 67-67 of FIG. 65.

FIG. 68 is an exploded view of the dock connector of FIG. 64.

FIG. 69 is a front view showing engagement of the dock connector of theair delivery tube with the intermediate component and the locking andcontact assembly provided to the reservoir dock according to an exampleof the present technology, the dock connector in an unlocked, engagedposition.

FIG. 70 is a cross-sectional view related to FIG. 69 showing the dockconnector in an unlocked, engaged position.

FIG. 71 is a top view related to FIG. 69 showing the dock connector inan unlocked, engaged position.

FIG. 72 is a cross-sectional view related to FIG. 69 showing the dockconnector in an unlocked, engaged position.

FIG. 73 is a front view showing engagement of the dock connector of theair delivery tube with the intermediate component and the locking andcontact assembly provided to the reservoir dock according to an exampleof the present technology, the dock connector in a locked position.

FIG. 74 is a cross-sectional view related to FIG. 73 showing the dockconnector in a locked position.

FIG. 75 is a top view related to FIG. 73 showing the dock connector in alocked position.

FIG. 76 is a cross-sectional view related to FIG. 73 showing the dockconnector in a locked position.

FIG. 77 is a side view related to FIG. 73 showing the dock connector ina locked position.

FIG. 78 is a cross-sectional view related to FIG. 73 showing the dockconnector in a locked position.

FIG. 79 is a perspective view of an integrated RPT device and humidifierwith the water reservoir inserted into the reservoir dock according toan example of the present technology.

FIG. 80 is a perspective view of the integrated RPT device andhumidifier of FIG. 79 with the water reservoir removed from thereservoir dock.

FIG. 81 is another perspective view of the integrated RPT device andhumidifier of FIG. 79 with the water reservoir removed from thereservoir dock.

FIG. 82 is a top perspective view of a water reservoir according to anexample of the present technology, the water reservoir in a closedposition.

FIG. 83 is a bottom perspective view of the water reservoir of FIG. 82.

FIG. 84 is a top perspective view of the water reservoir of FIG. 82 inan open position.

FIG. 85 is an exploded view of a lid of the water reservoir of FIG. 82.

FIG. 86 is an exploded view showing the lid and the base of the waterreservoir of FIG. 82.

FIG. 87 is an enlarged view showing a portion of the lid of FIG. 86.

FIG. 88 is an enlarged view showing a portion of the base of FIG. 86.

FIG. 89 is a side view of the water reservoir of FIG. 82 in an openposition.

FIG. 90 is a cross-sectional view showing a portion of the waterreservoir of FIG. 89.

FIG. 91 is a side view of the water reservoir of FIG. 82 in a closedposition.

FIG. 92 is a cross-sectional view showing a portion of the waterreservoir of FIG. 91.

FIG. 93 is another cross-sectional view showing a portion of the waterreservoir of FIG. 91.

FIG. 94 is a side view of the water reservoir of FIG. 82 showingassembly of the lid to the base according to an example of the presenttechnology.

FIG. 95 is cross-sectional view showing a portion of the water reservoirof FIG. 94.

FIG. 96 is a side view of the water reservoir of FIG. 82 showing aninitial stage of disassembling the lid from the base according to anexample of the present technology.

FIG. 97 is cross-sectional view showing a portion of the water reservoirof FIG. 96.

FIG. 98 is a cross-sectional view of the integrated RPT device andhumidifier of FIG. 79, taken along line 98-98 of FIG. 79.

FIG. 99 is an enlarged cross-sectional view showing a portion of theintegrated RPT device and humidifier of FIG. 98.

FIG. 100 is a cross-sectional view of the integrated RPT device andhumidifier of FIG. 79, taken along line 100-100 of FIG. 79.

FIG. 101 is an enlarged view showing a portion of the integrated RPTdevice and humidifier of FIG. 100.

FIG. 102 is an enlarged view showing another portion of the integratedRPT device and humidifier of FIG. 100.

FIG. 103 is an exploded view showing a heating assembly of a reservoirdock according to an example of the present technology.

FIG. 104 is an exploded view showing the support structure for theheated plate in the heating assembly of FIG. 103.

FIG. 105 is a cross-sectional view, taken along line 105-105 of FIG. 81,showing the heating assembly with the water reservoir removed from thereservoir dock according to an example of the present technology.

FIG. 106 is an enlarged cross-sectional view showing a portion of theheating assembly of FIG. 105.

FIG. 107 is an enlarged cross-sectional view of a portion of FIG. 98showing the heating assembly with the water reservoir inserted into thereservoir dock according to an example of the present technology.

FIG. 108 is an enlarged cross-sectional view showing a portion of theheating assembly of FIG. 107.

FIG. 109 is an enlarged cross-sectional view of a portion of FIG. 108and showing water drainage provided by the heating assembly according toan example of the present technology.

FIG. 110 is a perspective view showing a reservoir dock, an intermediatecomponent, and an air delivery tube according to an example of thepresent technology, the air delivery tube oriented for engagement withthe intermediate component and a contact assembly provided to thereservoir dock.

FIG. 111 is a perspective view showing the reservoir dock, theintermediate component and the air delivery tube of FIG. 110, the airdelivery tube fully engaged with the intermediate component.

FIG. 112 is a perspective view showing the reservoir dock engaged withthe intermediate component of FIG. 110.

FIG. 113 is an exploded view showing the reservoir dock, theintermediate component, and the air delivery tube of FIG. 110.

FIG. 114 is a perspective view showing the dock outlet of the reservoirdock of FIG. 110 with the intermediate component removed.

FIG. 115A is a perspective view showing the intermediate component andthe contact assembly provided to the reservoir dock of FIG. 110.

FIG. 115B is a cross-sectional view, taken along line 115B-115B of FIG.112, showing connection of the intermediate component to the reservoirdock according to an example of the present technology.

FIGS. 115C1, 115C2, and 115C3 are cross-sectional views, taken alongline 115C-115C of FIG. 110, showing an assembly sequence of theintermediate component to the reservoir dock according to an example ofthe present technology.

FIG. 115D is a cross-sectional view, taken along line 115D-115D of FIG.112, showing connection of the intermediate component to the reservoirdock according to an example of the present technology.

FIG. 115E is a cross-sectional view, taken along line 115E-115E of FIG.115D, showing connection of the intermediate component to the reservoirdock according to an example of the present technology.

FIG. 116 is a top perspective view of an intermediate componentaccording to an example of the present technology.

FIG. 117 is a bottom perspective view of the intermediate component ofFIG. 116.

FIG. 118 is a front view of the intermediate component of FIG. 116.

FIG. 119 is a top view of the intermediate component of FIG. 116.

FIG. 120 is an exploded view of the intermediate component of FIG. 116.

FIG. 121 is a perspective view showing the contact assembly provided tothe reservoir dock of FIG. 110 with the intermediate component removed.

FIG. 122 is an exploded view of the contact assembly of FIG. 121.

FIG. 123 is a perspective view of a dock connector for an air deliverytube according to an example of the present technology.

FIG. 124 is a front view of the dock connector of FIG. 123.

FIG. 125 is a cross-sectional view through line 125-125 of FIG. 124.

FIG. 126 is an exploded view of the dock connector of FIG. 123.

FIG. 127 is a top view showing engagement of the dock connector of theair delivery tube with the intermediate component according to anexample of the present technology, the dock connector in a lockedposition.

FIG. 128 is a cross-sectional view related to FIG. 127 showing the dockconnector in a locked position.

FIG. 129 is a side view showing engagement of the dock connector of theair delivery tube with the intermediate component and the contactassembly provided to the reservoir dock according to an example of thepresent technology, the dock connector in a locked position.

FIG. 130 is a cross-sectional view related to FIG. 129 showing the dockconnector in a locked position.

FIG. 131 is a cross-sectional view of the humidification portion of theintegrated RPT device and humidifier of FIG. 79, taken along line131-131 of FIG. 79.

FIG. 132 is an enlarged view showing a portion of the integrated RPTdevice and humidifier of FIG. 131.

FIG. 133 is an enlarged view showing another portion of the integratedRPT device and humidifier of FIG. 131.

FIG. 134 is an inverted bottom perspective view of a lid of the waterreservoir of FIG. 82.

FIG. 135 is an inverted cross-sectional view of the lid of FIG. 134,taken along line 135-135 of FIG. 134.

FIG. 136 is an inverted cross-sectional view of the lid of FIG. 134,taken along line 136-136 of FIG. 134.

5 DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

The following description is provided in relation to various exampleswhich may share one or more common characteristics and/or features. Itis to be understood that one or more features of any one example may becombinable with one or more features of another example or otherexamples. In addition, any single feature or combination of features inany of the examples may constitute a further example.

5.1 Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

In certain examples of the present technology, a supply of air atpositive pressure is provided to the nasal passages of the patient viaone or both nares.

In certain examples of the present technology, mouth breathing islimited, restricted or prevented.

5.2 Treatment Systems

In one form, the present technology comprises an apparatus or device fortreating a respiratory disorder. The apparatus or device may comprise anRPT device 4000 for supplying pressurised air to the patient 1000 via anair circuit 4170 to a patient interface 3000, e.g., see FIGS. 1A to 1C.

5.3 Patient Interface

FIG. 3A shows a non-invasive patient interface 3000 in accordance withone aspect of the present technology comprising the following functionalaspects: a seal-forming structure 3100, a plenum chamber 3200, apositioning and stabilising structure 3300, a vent 3400, one form ofconnection port 3600 for connection to air circuit 4170, and a foreheadsupport 3700. In some forms a functional aspect may be provided by oneor more physical components. In some forms, one physical component mayprovide one or more functional aspects. In use the seal-formingstructure 3100 is arranged to surround an entrance to the airways of thepatient so as to facilitate the supply of air at positive pressure tothe airways.

If a patient interface is unable to comfortably deliver a minimum levelof positive pressure to the airways, the patient interface may beunsuitable for respiratory pressure therapy.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 6 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 10 cmH₂O with respect to ambient.

The patient interface 3000 in accordance with one form of the presenttechnology is constructed and arranged to be able to provide a supply ofair at a positive pressure of at least 20 cmH₂O with respect to ambient.

5.4 RPT Device

An exploded view of an RPT device 4000 in accordance with one aspect ofthe present technology is shown in FIG. 5A. An RPT device 4000 maycomprise mechanical, pneumatic, and/or electrical components and beconfigured to execute one or more algorithms. The RPT device 4000 may beconfigured to generate a flow of air for delivery to a patient'sairways, such as to treat one or more of the respiratory conditionsdescribed elsewhere in the present document.

In one form, the RPT device 4000 is constructed and arranged to becapable of delivering a flow of air in a range of −20 L/min to +150L/min while maintaining a positive pressure of at least 6 cmH₂O, or atleast 10cmH₂O, or at least 20 cmH₂O.

The RPT device 4000 may include an external housing having one or morepanel(s) such as a main panel 4010, a front panel 4012 and a side panel4014. The RPT device 4000 may also comprise an outlet cap with a muffler4124 as shown in FIGS. 5A and 5B. The outlet cap with a muffler 4124 maybe removable and replaced with a water reservoir 5110 (see FIG. 5C). Insuch forms, the RPT device 4000 may be considered to include anintegrated humidifier 5000. Thus, the RPT device 4000 may be used withor without humidification depending upon whether the water reservoir5110 or the outlet cap with a muffler 4124 respectively is attached.Preferably the RPT device 4000 comprises a chassis 4016 that supportsone or more internal components of the RPT device 4000. In one form theRPT device 4000 comprises a pressure generator 4140, which may be housedin a pneumatic block 4020 coupled to the chassis 4016.

Further examples and details of an exemplary RPT device are described inPCT Publication No. WO 2015/089582, which is incorporated herein byreference in its entirety.

The pneumatic path of the RPT device 4000 (e.g. shown in FIG. 5D) maycomprise an inlet air filter 4112, an inlet muffler 4122, a pressuregenerator 4140 capable of supplying air at positive pressure (preferablya blower 4142) and an outlet muffler 4124 (or a water reservoir 5110 ifhumidification is required). One or more transducers 4270, such aspressure sensors and flow sensors may be included in the pneumatic path.The pneumatic path may also include anti-spill back valve 4160 toprevent water from the humidifier 5000 spilling back to the electricalcomponents of the RPT device 4000.

As shown in FIG. 5E, the RPT device 4000 may have an electrical powersupply 4210, one or more input devices 4220, a central controller 4230,a therapy device controller 4240, one or more protection circuits 4250,memory 4260, sensors/transducers 4270, data communication interface 4280and one or more output devices 4290. Electrical components 4200 may bemounted on a single Printed Circuit Board Assembly (PCBA) 4202 (e.g.,see FIG. 5A). In an alternative form, the RPT device 4000 may includemore than one PCBA 4202.

5.4.1 RPT Device Mechanical & Pneumatic Components

An RPT device may comprise one or more of the following components in anintegral unit. In an alternative form, one or more of the followingcomponents may be located as respective separate units.

5.4.1.1 Air filter(s)

An RPT device in accordance with one form of the present technology mayinclude an air filter 4110, or a plurality of air filters 4110.

In one form, an inlet air filter 4112 is located at the beginning of thepneumatic path upstream of a pressure generator 4140.

In one form, an outlet air filter 4114, for example an antibacterialfilter, is located between an outlet of the pneumatic block 4020 and apatient interface 3000.

5.4.1.2 Muffler(s)

An RPT device in accordance with one form of the present technology mayinclude a muffler 4120, or a plurality of mufflers 4120.

In one form of the present technology, an inlet muffler 4122 is locatedin the pneumatic path upstream of a pressure generator 4140.

In one form of the present technology, an outlet muffler 4124 is locatedin the pneumatic path between the pressure generator 4140 and a patientinterface 3000.

5.4.1.3 Pressure Generator

In one form of the present technology, a pressure generator 4140 forproducing a flow, or a supply, of air at positive pressure is acontrollable blower 4142. For example the blower 4142 may include abrushless DC motor 4144 with one or more impellers. The impellers may belocated in a volute. The blower may be capable of delivering a supply ofair, for example at a rate of up to about 120 litres/minute, at apositive pressure in a range from about 4 cmH₂O to about 20 cmH₂O, or inother forms up to about 30 cmH₂O. The blower may be as described in anyone of the following patents or patent applications the contents ofwhich are incorporated herein by reference in their entirety: U.S. Pat.Nos. 7,866,944; 8,638,014; 8,636,479; and PCT Patent ApplicationPublication No. WO 2013/020167.

The pressure generator 4140 is under the control of the therapy devicecontroller 4240.

In other forms, a pressure generator 4140 may be a piston-driven pump, apressure regulator connected to a high pressure source (e.g. compressedair reservoir), or a bellows.

5.4.1.4 Transducer(s)

Transducers may be internal of the RPT device, or external of the RPTdevice. External transducers may be located for example on or form partof the air circuit, e.g., the patient interface. External transducersmay be in the form of non-contact sensors such as a Doppler radarmovement sensor that transmit or transfer data to the RPT device.

In one form of the present technology, one or more transducers 4270 arelocated upstream and/or downstream of the pressure generator 4140. Theone or more transducers 4270 may be constructed and arranged to generatesignals representing properties of the flow of air such as a flow rate,a pressure or a temperature at that point in the pneumatic path.

In one form of the present technology, one or more transducers 4270 maybe located proximate to the patient interface 3000.

In one form, a signal from a transducer 4270 may be filtered, such as bylow-pass, high-pass or band-pass filtering.

5.4.1.4.1 Flow Rate Sensor

A flow rate sensor 4274 in accordance with the present technology may bebased on a differential pressure transducer, for example, an SDP600Series differential pressure transducer from SENSIRION.

In one form, a signal representing a flow rate from the flow rate sensor4274 is received by the central controller 4230.

5.4.1.4.2 Pressure Sensor

A pressure sensor 4272 in accordance with the present technology islocated in fluid communication with the pneumatic path. An example of asuitable pressure sensor is a transducer from the HONEYWELL ASDX series.An alternative suitable pressure sensor is a transducer from the NPASeries from GENERAL ELECTRIC.

In one form, a signal from the pressure sensor 4272 is received by thecentral controller 4230.

5.4.1.4.3 Motor Speed Transducer

In one form of the present technology a motor speed transducer 4276 isused to determine a rotational velocity of the motor 4144 and/or theblower 4142. A motor speed signal from the motor speed transducer 4276may be provided to the therapy device controller 4240. The motor speedtransducer 4276 may, for example, be a speed sensor, such as a Halleffect sensor.

5.4.1.5 Anti-Spill Back Valve

In one form of the present technology, an anti-spill back valve 4160 islocated between the humidifier 5000 and the pneumatic block 4020. Theanti-spill back valve is constructed and arranged to reduce the riskthat water will flow upstream from the humidifier 5000, for example tothe motor 4144.

5.4.2 RPT Device Electrical Components 5.4.2.1 Power Supply

A power supply 4210 may be located internal or external of the externalhousing 4010 of the RPT device 4000.

In one form of the present technology, power supply 4210 provideselectrical power to the RPT device 4000 only. In another form of thepresent technology, power supply 4210 provides electrical power to bothRPT device 4000 and humidifier 5000.

5.4.2.2 Input Devices

In one form of the present technology, an RPT device 4000 includes oneor more input devices 4220 in the form of buttons, switches or dials toallow a person to interact with the device. The buttons, switches ordials may be physical devices, or software devices accessible via atouch screen. The buttons, switches or dials may, in one form, bephysically connected to the external housing 4010, or may, in anotherform, be in wireless communication with a receiver that is in electricalconnection to the central controller 4230.

In one form, the input device 4220 may be constructed and arranged toallow a person to select a value and/or a menu option.

5.4.2.3 Central Controller

In one form of the present technology, the central controller 4230 isone or a plurality of processors suitable to control an RPT device 4000.

Suitable processors may include an ×86 INTEL processor, a processorbased on ARM® Cortex®-M processor from ARM Holdings such as an STM32series microcontroller from ST MICROELECTRONIC. In certain alternativeforms of the present technology, a 32-bit RISC CPU, such as an STR9series microcontroller from ST MICROELECTRONICS or a 16-bit RISC CPUsuch as a processor from the MSP430 family of microcontrollers,manufactured by TEXAS INSTRUMENTS may also be suitable.

In one form of the present technology, the central controller 4230 is adedicated electronic circuit.

In one form, the central controller 4230 is an application-specificintegrated circuit. In another form, the central controller 4230comprises discrete electronic components.

The central controller 4230 may be configured to receive input signal(s)from one or more transducers 4270, one or more input devices 4220, andthe humidifier 5000.

The central controller 4230 may be configured to provide outputsignal(s) to one or more of an output device 4290, a therapy devicecontroller 4240, a data communication interface 4280, and the humidifier5000.

In some forms of the present technology, the central controller 4230 isconfigured to implement the one or more methodologies described herein,such as the one or more algorithms 4300 expressed as computer programsstored in a non-transitory computer readable storage medium, such asmemory 4260. In some forms of the present technology, the centralcontroller 4230 may be integrated with an RPT device 4000. However, insome forms of the present technology, some methodologies may beperformed by a remotely located device. For example, the remotelylocated device may determine control settings for a ventilator or detectrespiratory related events by analysis of stored data such as from anyof the sensors described herein.

5.4.2.4 Clock

The RPT device 4000 may include a clock 4232 that is connected to thecentral controller 4230.

5.4.2.5 Therapy Device Controller

In one form of the present technology, therapy device controller 4240 isa therapy control module 4330 that forms part of the algorithms 4300executed by the central controller 4230.

In one form of the present technology, therapy device controller 4240 isa dedicated motor control integrated circuit. For example, in one form aMC33035 brushless DC motor controller, manufactured by ONSEMI is used.

5.4.2.6 Protection Circuits

The one or more protection circuits 4250 in accordance with the presenttechnology may comprise an electrical protection circuit, a temperatureand/or pressure safety circuit.

5.4.2.7 Memory

In accordance with one form of the present technology the RPT device4000 includes memory 4260, e.g., non-volatile memory. In some forms,memory 4260 may include battery powered static RAM. In some forms,memory 4260 may include volatile RAM.

Memory 4260 may be located on the PCBA 4202. Memory 4260 may be in theform of EEPROM, or NAND flash.

Additionally or alternatively, RPT device 4000 includes a removable formof memory 4260, for example a memory card made in accordance with theSecure Digital (SD) standard.

In one form of the present technology, the memory 4260 acts as anon-transitory computer readable storage medium on which is storedcomputer program instructions expressing the one or more methodologiesdescribed herein, such as the one or more algorithms 4300.

5.4.2.8 Data Communication Systems

In one form of the present technology, a data communication interface4280 is provided, and is connected to the central controller 4230. Datacommunication interface 4280 may be connectable to a remote externalcommunication network 4282 and/or a local external communication network4284. The remote external communication network 4282 may be connectableto a remote external device 4286. The local external communicationnetwork 4284 may be connectable to a local external device 4288.

In one form, data communication interface 4280 is part of the centralcontroller 4230. In another form, data communication interface 4280 isseparate from the central controller 4230, and may comprise anintegrated circuit or a processor.

In one form, remote external communication network 4282 is the Internet.The data communication interface 4280 may use wired communication (e.g.via Ethernet, or optical fibre) or a wireless protocol (e.g. CDMA, GSM,LTE) to connect to the Internet.

In one form, local external communication network 4284 utilises one ormore communication standards, such as Bluetooth, or a consumer infraredprotocol.

In one form, remote external device 4286 is one or more computers, forexample a cluster of networked computers. In one form, remote externaldevice 4286 may be virtual computers, rather than physical computers. Ineither case, such a remote external device 4286 may be accessible to anappropriately authorised person such as a clinician.

The local external device 4288 may be a personal computer, mobile phone,tablet or remote control.

5.4.2.9 Output Devices Including Optional Display, Alarms

An output device 4290 in accordance with the present technology may takethe form of one or more of a visual, audio and haptic unit. A visualdisplay may be a Liquid Crystal Display (LCD) or Light Emitting Diode(LED) display.

5.4.2.9.1 Display Driver

A display driver 4292 receives as an input the characters, symbols, orimages intended for display on the display 4294, and converts them tocommands that cause the display 4294 to display those characters,symbols, or images.

5.4.2.9.2 Display

A display 4294 is configured to visually display characters, symbols, orimages in response to commands received from the display driver 4292.For example, the display 4294 may be an eight-segment display, in whichcase the display driver 4292 converts each character or symbol, such asthe figure “0”, to eight logical signals indicating whether the eightrespective segments are to be activated to display a particularcharacter or symbol.

5.4.3 RPT Device Algorithms

As mentioned above, in some forms of the present technology, the centralcontroller 4230 may be configured to implement one or more algorithms4300 expressed as computer programs stored in a non-transitory computerreadable storage medium, such as memory 4260. The algorithms 4300 aregenerally grouped into groups referred to as modules, e.g., see FIG. 5F.

5.4.3.1 Pre-Processing Module

A pre-processing module 4310 in accordance with one form of the presenttechnology receives as an input a signal from a transducer 4270, forexample a flow rate sensor 4274 or pressure sensor 4272, and performsone or more process steps to calculate one or more output values thatwill be used as an input to another module, for example a therapy enginemodule 4320.

In one form of the present technology, the output values include theinterface or mask pressure Pm, the respiratory flow rate Qr, and theleak flow rate Ql.

In various forms of the present technology, the pre-processing module4310 comprises one or more of the following algorithms: pressurecompensation 4312, vent flow rate estimation 4314, leak flow rateestimation 4316, and respiratory flow rate estimation 4318.

5.4.3.1.1 Pressure Compensation

In one form of the present technology, a pressure compensation algorithm4312 receives as an input a signal indicative of the pressure in thepneumatic path proximal to an outlet of the pneumatic block. Thepressure compensation algorithm 4312 estimates the pressure drop throughthe air circuit 4170 and provides as an output an estimated pressure,Pm, in the patient interface 3000.

5.4.3.1.2 Vent Flow Rate Estimation

In one form of the present technology, a vent flow rate estimationalgorithm 4314 receives as an input an estimated pressure, Pm, in thepatient interface 3000 and estimates a vent flow rate of air, Qv, from avent 3400 in a patient interface 3000.

5.4.3.1.3 Leak Flow Rate Estimation

In one form of the present technology, a leak flow rate estimationalgorithm 4316 receives as an input a total flow rate, Qt, and a ventflow rate Qv, and provides as an output an estimate of the leak flowrate Ql. In one form, the leak flow rate estimation algorithm estimatesthe leak flow rate Ql by calculating an average of the differencebetween total flow rate Qt and vent flow rate Qv over a periodsufficiently long to include several breathing cycles, e.g. about 10seconds.

In one form, the leak flow rate estimation algorithm 4316 receives as aninput a total flow rate Qt, a vent flow rate Qv, and an estimatedpressure, Pm, in the patient interface 3000, and provides as an output aleak flow rate Ql, by calculating a leak conductance, and determining aleak flow rate Ql to be a function of leak conductance and pressure, Pm.Leak conductance is calculated as the quotient of low pass filterednon-vent flow rate equal to the difference between total flow rate Qtand vent flow rate Qv, and low pass filtered square root of pressure Pm,where the low pass filter time constant has a value sufficiently long toinclude several breathing cycles, e.g. about 10 seconds. The leak flowrate Ql may be estimated as the product of leak conductance and afunction of pressure, Pm.

5.4.3.1.4 Respiratory Flow Rate Estimation

In one form of the present technology, a respiratory flow rateestimation algorithm 4318 receives as an input a total flow rate, Qt, avent flow rate, Qv, and a leak flow rate, Ql, and estimates arespiratory flow rate of air, Qr, to the patient, by subtracting thevent flow rate Qv and the leak flow rate Ql from the total flow rate Qt.

5.4.3.2 Therapy Engine Module

In one form of the present technology, a therapy engine module 4320receives as inputs one or more of a pressure, Pm, in a patient interface3000, and a respiratory flow rate of air to a patient, Qr, and providesas an output one or more therapy parameters.

In one form of the present technology, a therapy parameter is atreatment pressure Pt.

In one form of the present technology, therapy parameters are one ormore of an amplitude of a pressure variation, a base pressure, and atarget ventilation.

In various forms, the therapy engine module 4320 comprises one or moreof the following algorithms: phase determination 4321, waveformdetermination 4322, ventilation determination 4323, inspiratory flowlimitation determination 4324, apnea/hypopnea determination 4325, snoredetermination 4326, airway patency determination 4327, targetventilation determination 4328, and therapy parameter determination4329.

5.4.3.2.1 Phase Determination

In one form of the present technology, the RPT device 4000 does notdetermine phase.

In one form of the present technology, a phase determination algorithm4321 receives as an input a signal indicative of respiratory flow rate,Qr, and provides as an output a phase Φ of a current breathing cycle ofa patient 1000.

In some forms, known as discrete phase determination, the phase output Φis a discrete variable. One implementation of discrete phasedetermination provides a bi-valued phase output Φ with values of eitherinhalation or exhalation, for example represented as values of 0 and 0.5revolutions respectively, upon detecting the start of spontaneousinhalation and exhalation respectively. RPT devices 4000 that “trigger”and “cycle” effectively perform discrete phase determination, since thetrigger and cycle points are the instants at which the phase changesfrom exhalation to inhalation and from inhalation to exhalation,respectively. In one implementation of bi-valued phase determination,the phase output Φ is determined to have a discrete value of 0 (thereby“triggering” the RPT device 4000) when the respiratory flow rate Qr hasa value that exceeds a positive threshold, and a discrete value of 0.5revolutions (thereby “cycling” the RPT device 4000) when a respiratoryflow rate Qr has a value that is more negative than a negativethreshold. The inhalation time Ti and the exhalation time Te may beestimated as typical values over many respiratory cycles of the timespent with phase Φ equal to 0 (indicating inspiration) and 0.5(indicating expiration) respectively.

Another implementation of discrete phase determination provides atri-valued phase output Φ with a value of one of inhalation,mid-inspiratory pause, and exhalation.

In other forms, known as continuous phase determination, the phaseoutput Φ is a continuous variable, for example varying from 0 to 1revolutions, or 0 to 2π radians. RPT devices 4000 that performcontinuous phase determination may trigger and cycle when the continuousphase reaches 0 and 0.5 revolutions, respectively. In one implementationof continuous phase determination, a continuous value of phase Φ isdetermined using a fuzzy logic analysis of the respiratory flow rate Qr.A continuous value of phase determined in this implementation is oftenreferred to as “fuzzy phase”. In one implementation of a fuzzy phasedetermination algorithm 4321, the following rules are applied to therespiratory flow rate Qr:

1. If the respiratory flow rate is zero and increasing fast then thephase is 0 revolutions.2. If the respiratory flow rate is large positive and steady then thephase is 0.25 revolutions.3. If the respiratory flow rate is zero and falling fast, then the phaseis 0.5 revolutions.4. If the respiratory flow rate is large negative and steady then thephase is 0.75 revolutions.5. If the respiratory flow rate is zero and steady and the 5-secondlow-pass filtered absolute value of the respiratory flow rate is largethen the phase is 0.9 revolutions.6. If the respiratory flow rate is positive and the phase is expiratory,then the phase is 0 revolutions.7. If the respiratory flow rate is negative and the phase isinspiratory, then the phase is 0.5 revolutions.8. If the 5-second low-pass filtered absolute value of the respiratoryflow rate is large, the phase is increasing at a steady rate equal tothe patient's breathing rate, low-pass filtered with a time constant of20 seconds.

The output of each rule may be represented as a vector whose phase isthe result of the rule and whose magnitude is the fuzzy extent to whichthe rule is true. The fuzzy extent to which the respiratory flow rate is“large”, “steady”, etc. is determined with suitable membershipfunctions. The results of the rules, represented as vectors, are thencombined by some function such as taking the centroid. In such acombination, the rules may be equally weighted, or differently weighted.

In another implementation of continuous phase determination, the phase Φis first discretely estimated from the respiratory flow rate Qr asdescribed above, as are the inhalation time Ti and the exhalation timeTe. The continuous phase Φ at any instant may be determined as the halfthe proportion of the inhalation time Ti that has elapsed since theprevious trigger instant, or 0.5 revolutions plus half the proportion ofthe exhalation time Te that has elapsed since the previous cycle instant(whichever instant was more recent).

5.4.3.2.2 Waveform Determination

In one form of the present technology, the therapy parameterdetermination algorithm 4329 provides an approximately constanttreatment pressure throughout a respiratory cycle of a patient.

In other forms of the present technology, the therapy control module4330 controls the pressure generator 4140 to provide a treatmentpressure Pt that varies as a function of phase Φ of a respiratory cycleof a patient according to a waveform template Π(Φ).

In one form of the present technology, a waveform determinationalgorithm 4322 provides a waveform template Π(Φ) with values in therange [0, 1] on the domain of phase values Φ provided by the phasedetermination algorithm 4321 to be used by the therapy parameterdetermination algorithm 4329.

In one form, suitable for either discrete or continuously-valued phase,the waveform template Π(Φ) is a square-wave template, having a value of1 for values of phase up to and including 0.5 revolutions, and a valueof 0 for values of phase above 0.5 revolutions. In one form, suitablefor continuously-valued phase, the waveform template Π(Φ) comprises twosmoothly curved portions, namely a smoothly curved (e.g. raised cosine)rise from 0 to 1 for values of phase up to 0.5 revolutions, and asmoothly curved (e.g. exponential) decay from 1 to 0 for values of phaseabove 0.5 revolutions. In one form, suitable for continuously-valuedphase, the waveform template Π(Φ) is based on a square wave, but with asmooth rise from 0 to 1 for values of phase up to a “rise time” that isless than 0.5 revolutions, and a smooth fall from 1 to 0 for values ofphase within a “fall time” after 0.5 revolutions, with a “fall time”that is less than 0.5 revolutions.

In some forms of the present technology, the waveform determinationalgorithm 4322 selects a waveform template Π(Φ) from a library ofwaveform templates, dependent on a setting of the RPT device. Eachwaveform template Π(Φ) in the library may be provided as a lookup tableof values H against phase values Φ. In other forms, the waveformdetermination algorithm 4322 computes a waveform template Π(Φ) “on thefly” using a predetermined functional form, possibly parameterised byone or more parameters (e.g. time constant of an exponentially curvedportion). The parameters of the functional form may be predetermined ordependent on a current state of the patient 1000.

In some forms of the present technology, suitable for discrete bi-valuedphase of either inhalation (Φ=0 revolutions) or exhalation (Φ=0.5revolutions), the waveform determination algorithm 4322 computes awaveform template Π “on the fly” as a function of both discrete phase Φand time t measured since the most recent trigger instant. In one suchform, the waveform determination algorithm 4322 computes the waveformtemplate Π(Φ, t) in two portions (inspiratory and expiratory) asfollows:

${\Pi\left( {\Phi,t} \right)} = \left\{ \begin{matrix}{{\Pi_{i}(t)}\ ,} & {\Phi = 0} \\{{\Pi_{e}\left( {t - T_{i}} \right)}\ ,} & {\Phi = 0.5}\end{matrix} \right.$

where Π_(i)(t) and Π_(e)(t) are inspiratory and expiratory portions ofthe waveform template Π(Φ, t). In one such form, the inspiratory portionΠ_(i)(t) of the waveform template is a smooth rise from 0 to 1parameterised by a rise time, and the expiratory portion Π_(e)(t) of thewaveform template is a smooth fall from 1 to 0 parameterised by a falltime.

5.4.3.2.3 Ventilation Determination

In one form of the present technology, a ventilation determinationalgorithm 4323 receives an input a respiratory flow rate Qr, anddetermines a measure indicative of current patient ventilation, Vent.

In some implementations, the ventilation determination algorithm 4323determines a measure of ventilation Vent that is an estimate of actualpatient ventilation. One such implementation is to take half theabsolute value of respiratory flow rate, Qr, optionally filtered bylow-pass filter such as a second order Bessel low-pass filter with acorner frequency of 0.11 Hz.

In other implementations, the ventilation determination algorithm 4323determines a measure of ventilation Vent that is broadly proportional toactual patient ventilation. One such implementation estimates peakrespiratory flow rate Qpeak over the inspiratory portion of the cycle.This and many other procedures involving sampling the respiratory flowrate Qr produce measures which are broadly proportional to ventilation,provided the flow rate waveform shape does not vary very much (here, theshapes of two breaths are taken to be similar when the flow ratewaveforms of the breaths normalised in time and amplitude are similar).Some simple examples include the median positive respiratory flow rate,the median of the absolute value of respiratory flow rate, and thestandard deviation of flow rate. Arbitrary linear combinations ofarbitrary order statistics of the absolute value of respiratory flowrate using positive coefficients, and even some using both positive andnegative coefficients, are approximately proportional to ventilation.Another example is the mean of the respiratory flow rate in the middle Kproportion (by time) of the inspiratory portion, where 0<K<1. There isan arbitrarily large number of measures that are exactly proportional toventilation if the flow rate shape is constant.

5.4.3.2.4 Determination of Inspiratory Flow Limitation

In one form of the present technology, the central controller 4230executes an inspiratory flow limitation determination algorithm 4324 forthe determination of the extent of inspiratory flow limitation.

In one form, the inspiratory flow limitation determination algorithm4324 receives as an input a respiratory flow rate signal Qr and providesas an output a metric of the extent to which the inspiratory portion ofthe breath exhibits inspiratory flow limitation.

In one form of the present technology, the inspiratory portion of eachbreath is identified by a zero-crossing detector. A number of evenlyspaced points (for example, sixty-five), representing points in time,are interpolated by an interpolator along the inspiratory flow rate-timecurve for each breath. The curve described by the points is then scaledby a scalar to have unity length (duration/period) and unity area toremove the effects of changing breathing rate and depth. The scaledbreaths are then compared in a comparator with a pre-stored templaterepresenting a normal unobstructed breath, similar to the inspiratoryportion of the breath shown in FIG. 6A. Breaths deviating by more than aspecified threshold (typically 1 scaled unit) at any time during theinspiration from this template, such as those due to coughs, sighs,swallows and hiccups, as determined by a test element, are rejected. Fornon-rejected data, a moving average of the first such scaled point iscalculated by the central controller 4230 for the preceding severalinspiratory events. This is repeated over the same inspiratory eventsfor the second such point, and so on. Thus, for example, sixty fivescaled data points are generated by the central controller 4230, andrepresent a moving average of the preceding several inspiratory events,e.g., three events. The moving average of continuously updated values ofthe (e.g., sixty five) points are hereinafter called the “scaled flowrate”, designated as Qs(t). Alternatively, a single inspiratory eventcan be utilised rather than a moving average.

From the scaled flow rate, two shape factors relating to thedetermination of partial obstruction may be calculated.

Shape factor 1 is the ratio of the mean of the middle (e.g. thirty-two)scaled flow rate points to the mean overall (e.g. sixty-five) scaledflow rate points. Where this ratio is in excess of unity, the breathwill be taken to be normal. Where the ratio is unity or less, the breathwill be taken to be obstructed. A ratio of about 1.17 is taken as athreshold between partially obstructed and unobstructed breathing, andequates to a degree of obstruction that would permit maintenance ofadequate oxygenation in a typical patient.

Shape factor 2 is calculated as the RMS deviation from unit scaled flowrate, taken over the middle (e.g. thirty two) points. An RMS deviationof about 0.2 units is taken to be normal. An RMS deviation of zero istaken to be a totally flow-limited breath. The closer the RMS deviationto zero, the breath will be taken to be more flow limited.

Shape factors 1 and 2 may be used as alternatives, or in combination. Inother forms of the present technology, the number of sampled points,breaths and middle points may differ from those described above.Furthermore, the threshold values can be other than those described.

5.4.3.2.5 Determination of Apneas and Hypopneas

In one form of the present technology, the central controller 4230executes an apnea/hypopnea determination algorithm 4325 for thedetermination of the presence of apneas and/or hypopneas.

In one form, the apnea/hypopnea determination algorithm 4325 receives asan input a respiratory flow rate signal Qr and provides as an output aflag that indicates that an apnea or a hypopnea has been detected.

In one form, an apnea will be said to have been detected when a functionof respiratory flow rate Qr falls below a flow rate threshold for apredetermined period of time. The function may determine a peak flowrate, a relatively short-term mean flow rate, or a flow rateintermediate of relatively short-term mean and peak flow rate, forexample an RMS flow rate. The flow rate threshold may be a relativelylong-term measure of flow rate.

In one form, a hypopnea will be said to have been detected when afunction of respiratory flow rate Qr falls below a second flow ratethreshold for a predetermined period of time. The function may determinea peak flow, a relatively short-term mean flow rate, or a flow rateintermediate of relatively short-term mean and peak flow rate, forexample an RMS flow rate. The second flow rate threshold may be arelatively long-term measure of flow rate. The second flow ratethreshold is greater than the flow rate threshold used to detect apneas.

5.4.3.2.6 Determination of Snore

In one form of the present technology, the central controller 4230executes one or more snore determination algorithms 4326 for thedetermination of the extent of snore.

In one form, the snore determination algorithm 4326 receives as an inputa respiratory flow rate signal Qr and provides as an output a metric ofthe extent to which snoring is present.

The snore determination algorithm 4326 may comprise the step ofdetermining the intensity of the flow rate signal in the range of 30-300Hz. Further, the snore determination algorithm 4326 may comprise a stepof filtering the respiratory flow rate signal Qr to reduce backgroundnoise, e.g., the sound of airflow in the system from the blower.

5.4.3.2.7 Determination of Airway Patency

In one form of the present technology, the central controller 4230executes one or more airway patency determination algorithms 4327 forthe determination of the extent of airway patency.

In one form, the airway patency determination algorithm 4327 receives asan input a respiratory flow rate signal Qr, and determines the power ofthe signal in the frequency range of about 0.75 Hz and about 3 Hz. Thepresence of a peak in this frequency range is taken to indicate an openairway. The absence of a peak is taken to be an indication of a closedairway.

In one form, the frequency range within which the peak is sought is thefrequency of a small forced oscillation in the treatment pressure Pt. Inone implementation, the forced oscillation is of frequency 2 Hz withamplitude about 1 cmH₂O.

In one form, airway patency determination algorithm 4327 receives as aninput a respiratory flow rate signal Qr, and determines the presence orabsence of a cardiogenic signal. The absence of a cardiogenic signal istaken to be an indication of a closed airway.

5.4.3.2.8 Determination of Target Ventilation

In one form of the present technology, the central controller 4230 takesas input the measure of current ventilation, Vent, and executes one ormore target ventilation determination algorithms 4328 for thedetermination of a target value Vtgt for the measure of ventilation.

In some forms of the present technology, there is no target ventilationdetermination algorithm 4328, and the target value Vtgt ispredetermined, for example by hard-coding during configuration of theRPT device 4000 or by manual entry through the input device 4220.

In other forms of the present technology, such as adaptiveservo-ventilation (ASV), the target ventilation determination algorithm4328 computes a target value Vtgt from a value Vtyp indicative of thetypical recent ventilation of the patient.

In some forms of adaptive servo-ventilation, the target ventilation Vtgtis computed as a high proportion of, but less than, the typical recentventilation Vtyp. The high proportion in such forms may be in the range(80%, 100%), or (85%, 95%), or (87%, 92%).

In other forms of adaptive servo-ventilation, the target ventilationVtgt is computed as a slightly greater than unity multiple of thetypical recent ventilation Vtyp.

The typical recent ventilation Vtyp is the value around which thedistribution of the measure of current ventilation Vent over multipletime instants over some predetermined timescale tends to cluster, thatis, a measure of the central tendency of the measure of currentventilation over recent history. In one implementation of the targetventilation determination algorithm 4328, the recent history is of theorder of several minutes, but in any case should be longer than thetimescale of Cheyne-Stokes waxing and waning cycles. The targetventilation determination algorithm 4328 may use any of the variety ofwell-known measures of central tendency to determine the typical recentventilation Vtyp from the measure of current ventilation, Vent. One suchmeasure is the output of a low-pass filter on the measure of currentventilation Vent, with time constant equal to one hundred seconds.

5.4.3.2.9 Determination of Therapy Parameters

In some forms of the present technology, the central controller 4230executes one or more therapy parameter determination algorithms 4329 forthe determination of one or more therapy parameters using the valuesreturned by one or more of the other algorithms in the therapy enginemodule 4320.

In one form of the present technology, the therapy parameter is aninstantaneous treatment pressure Pt. In one implementation of this form,the therapy parameter determination algorithm 4329 determines thetreatment pressure Pt using the equation

Pt=AΠ(Φ,t)+P ₀  (1)

where:

-   -   A is the amplitude,    -   Π(Φ, t) is the waveform template value (in the range 0 to 1) at        the current value t of phase and t of time, and    -   P₀ is a base pressure.

If the waveform determination algorithm 4322 provides the waveformtemplate Π(Φ, t) as a lookup table of values H indexed by phase Φ, thetherapy parameter determination algorithm 4329 applies equation (1) bylocating the nearest lookup table entry to the current value Φ of phasereturned by the phase determination algorithm 4321, or by interpolationbetween the two entries straddling the current value Φ of phase.

The values of the amplitude A and the base pressure P₀ may be set by thetherapy parameter determination algorithm 4329 depending on the chosenrespiratory pressure therapy mode in the manner described below.

5.4.3.3 Therapy Control Module

The therapy control module 4330 in accordance with one aspect of thepresent technology receives as inputs the therapy parameters from thetherapy parameter determination algorithm 4329 of the therapy enginemodule 4320, and controls the pressure generator 4140 to deliver a flowof air in accordance with the therapy parameters.

In one form of the present technology, the therapy parameter is atreatment pressure Pt, and the therapy control module 4330 controls thepressure generator 4140 to deliver a flow of air whose mask pressure Pmat the patient interface 3000 is equal to the treatment pressure Pt.

5.4.3.4 Detection of Fault Conditions

In one form of the present technology, the central controller 4230executes one or more methods 4340 for the detection of fault conditions.The fault conditions detected by the one or more methods 4340 mayinclude at least one of the following:

-   -   Power failure (no power, or insufficient power)    -   Transducer fault detection    -   Failure to detect the presence of a component    -   Operating parameters outside recommended ranges (e.g. pressure,        flow rate, temperature, PaO₂)    -   Failure of a test alarm to generate a detectable alarm signal.

Upon detection of the fault condition, the corresponding algorithm 4340signals the presence of the fault by one or more of the following:

-   -   Initiation of an audible, visual &/or kinetic (e.g. vibrating)        alarm    -   Sending a message to an external device    -   Logging of the incident

5.5 Air Circuit

An air circuit 4170 in accordance with an aspect of the presenttechnology is a conduit or a tube constructed and arranged to allow, inuse, a flow of air to travel between two components such as RPT device4000 and the patient interface 3000.

In particular, the air circuit 4170 may be in fluid connection with theoutlet of the pneumatic block 4020 and the patient interface. The aircircuit may be referred to as an air delivery tube. In some cases theremay be separate limbs of the circuit for inhalation and exhalation. Inother cases a single limb is used.

In some forms, the air circuit 4170 may comprise one or more heatingelements configured to heat air in the air circuit, for example tomaintain or raise the temperature of the air. The heating element may bein a form of a heated wire circuit, and may comprise one or moretransducers, such as temperature sensors. In one form, the heated wirecircuit may be helically wound around the axis of the air circuit 4170.The heating element may be in communication with a controller such as acentral controller 4230. One example of an air circuit 4170 comprising aheated wire circuit is described in U.S. Pat. No. 8,733,349, which isincorporated herewithin in its entirety by reference.

5.5.1 Oxygen Delivery

In one form of the present technology, supplemental oxygen 4180 isdelivered to one or more points in the pneumatic path, such as upstreamof the pneumatic block 4020, to the air circuit 4170 and/or to thepatient interface 3000.

5.6 Humidifier 5.6.1 Humidifier Overview

In one form of the present technology there is provided a humidifier5000 (e.g., as shown in FIG. 5C) to change the absolute humidity of airor gas for delivery to a patient relative to ambient air. Typically, thehumidifier 5000 is used to increase the absolute humidity and increasethe temperature of the flow of air (relative to ambient air) beforedelivery to the patient's airways.

RPT Device and Humidifier

FIGS. 6A, 6B, 7, and 8A to 8D illustrate an integrated RPT device andhumidifier 6000 according to an example of the present technology. Asillustrated, the integrated RPT device and humidifier 6000 includes areservoir dock 6050 structured and arranged to receive a water reservoir6100 (also referred to as a humidifier tub or a humidifier reservoir).In the illustrated example, the integrated RPT device and humidifier6000 comprises a humidifier that is integrated with an RPT device suchthat a pneumatic block 7100 of the RPT device comprises components thatperform the function of the RPT device as well as components thatperform the function of the humidifier. For example, as shown in FIG. 7,the reservoir dock 6050 is integrated with the pneumatic block 7100 ofthe RPT device to provide an integral unit, with the reservoir dock 6050structured and arranged to receive the water reservoir 6100.

It should be appreciated that the humidifier (e.g., reservoir dock 6050)may be provided separately to the RPT device (e.g., pneumatic block7100) in an alternative arrangement. In such arrangement, additionalinterfaces may be used to connect the humidifier (e.g., reservoir dock6050) to the RPT device (e.g., pneumatic block 7100).

The RPT device comprises a blower supported within the pneumatic block7100. The blower is structured and arranged for producing a flow, or asupply, of air at positive pressure, e.g., in the range of 2-50 cmH₂O.In an example, the blower may include a single stage design or amulti-stage design, e.g., two or more stage designs. The blower isoperable to draw a supply of air into the pneumatic block 7100, e.g.,through one or more intake openings in the pneumatic block, and into aninlet thereof (blower inlet), and provide a pressurized supply of air atan outlet (blower outlet). Examples and details of an exemplary blowerare described in PCT Patent Application Publication No. WO 2013/020167,which is incorporated herein by reference in its entirety. The bloweroutlet is communicated with the humidifier, e.g., an inlet of the waterreservoir 6100.

The pneumatic block 7100 includes a chassis assembly 7300, e.g.,including a top chassis and a bottom chassis. The chassis assembly 7300includes a chassis inlet 7310 (e.g., see FIG. 20E) and a chassis outlet7320 (e.g., see FIGS. 20F and 21). In an example, an external housing8002, including one or more panels and/or one or more userinputs/displays, may enclose the pneumatic block 7100, e.g., see FIGS.6A and 6B. The chassis assembly 7300 supports and/or houses internalcomponents of the pneumatic block 7100, e.g., the blower. The chassisassembly 7300 also supports a printed circuit board assembly (PCBA)7600. The chassis assembly 7300 and internal components of the pneumaticblock cooperate to form a pneumatic air flow path that extends from thechassis inlet 7310 to the blower inlet of the blower and from the bloweroutlet of the blower to the chassis outlet 7320. The chassis outlet 7320is adapted to communicate with the reservoir dock 6050 and an inlet ofthe water reservoir 6100 when the water reservoir is received in thereservoir dock 6050. The reservoir dock 6050 is also configured andarranged to allow communication between an outlet of the water reservoir6100 and the air circuit 4170 as described in greater detail below.

Whilst most of the described examples are based on a description of theair circuit or air delivery tube being attachable to a water reservoirdock, it should be appreciated that in some air delivery systems thereis no humidification and water reservoir present in the system. In thiscase, the air delivery tube is directly or indirectly connectable to atube engagement dock of the RPT device. All of the above disclosurerelated to the water reservoir connecting dock is also applicable to therespective tube engagement of the RPT device in such cases.

Also, the RPT device and/or humidifier provides one form of connectionor engagement port for connecting to the air circuit or air deliverytube 4170, i.e., the place where the air delivery tube 4170 engages withthe RPT device and/or humidifier. In below described examples, theconnection or engagement port may comprise the outlet tube 6130 (outlet)of the water reservoir 6100, the outlet of the outlet muffler 4124, theintermediate component 6700, or the intermediate component 9700, forexample. The function of the connection or engagement port is to pass onpressurized air generated in the RPT device to the air delivery tube andthe patient interface, and as such may be used with an RPT device withor without a humidifier. In examples, the connection or engagement portmay also locate, secure and/or electrically connect to the air deliverytube. Also, it should be appreciated that the connection or engagementport may be located anywhere on the RPT device and/or humidifier, aslong as it is communicated (e.g., via one or more intermediateconnectors) with the pressurised flow source of the RPT device and/orthe humidifier (e.g., water reservoir). For example, the connection orengagement port may form part of the water reservoir dock, or may bepositioned elsewhere (i.e., not part of the water reservoir dock) andcommunicated with the water reservoir dock, water reservoir thereof orthe pneumatic block of the RPT device.

5.6.2 Humidifier Components 5.6.2.1 Water Reservoir

FIGS. 6B and 9 show a water reservoir 6100 according to an example ofthe present technology. The water reservoir 6100 is configured to hold,or retain, a volume of liquid (e.g. water) to be evaporated forhumidification of the flow of air. The water reservoir 6100 may beconfigured to hold a predetermined maximum volume of water in order toprovide adequate humidification for at least the duration of arespiratory therapy session, such as one evening of sleep. Typically,the water reservoir is configured to hold several hundred millilitres ofwater, e.g. 300 millilitres (ml), 325 ml, 350 ml or 400 ml, although itis to be understood that other volumes of liquid may be utilised, e.g.,at least 100 ml. In other forms, the humidifier may be configured toreceive a supply of water from an external water source such as abuilding's water supply system.

In the illustrated example, the water reservoir 6100 includes areservoir base 6112 (also referred to as a reservoir body, a humidifiertub base, or a humidifier tub body) and a reservoir lid 6114 (alsoreferred to as a humidifier tub lid) removably coupled to the reservoirbase 6112. A deformable seal may be provided to the reservoir lid and/orto the reservoir base, e.g., see deformable peripheral seal 6116provided to periphery of reservoir lid 6114 in FIG. 19C. When thereservoir lid 6114 is coupled to the reservoir base 6112, the seal 6116is structured and arranged to engage between the lid 6114 and the base6112 to seal the lid and the base and prevent egress of water from thewater reservoir. The reservoir lid 6114 may be structured to be fullyremovable from the reservoir base 6112, e.g., for patient usability toclean the interior of the reservoir base and/or the reservoir lid. In analternative example, the reservoir lid 6114 may be permanently attachedto the reservoir base 6112.

According to one aspect, the water reservoir 6100 is configured to addhumidity to a flow of air from the RPT device as the flow of air travelstherethrough. In one form, the water reservoir 6100 may be configured toencourage the flow of air to travel in a tortuous path through thereservoir while in contact with the volume of water therein. Forexample, the water reservoir 6100 may comprise one or more flowelements, e.g., baffles, to encourage a tortuous flow path.

As described in more detail below, the water reservoir 6100 may beremovably coupled with the reservoir dock 6050. In an example,insertion/removal of the water reservoir may be provided along a pathextending in an anterior-posterior direction. In an alternative example,at least a portion of the path for insertion/removal of the waterreservoir may extend in an inferior-superior direction, e.g., at least aportion of the path for insertion includes a slope or drop down into anoperative position.

The water reservoir 6100 may also be configured to discourage egress ofliquid therefrom, such as when the reservoir is displaced and/or rotatedfrom its normal, working orientation, such as through any aperturesand/or in between its sub-components. As the flow of air to behumidified by the humidifier is typically pressurised, the reservoir mayalso be configured to prevent losses in pneumatic pressure through leakand/or flow impedance.

Reservoir Base

As shown in FIG. 9, the reservoir base 6112 comprises a main body 6140including a plurality of walls and a conductive portion 6150, typicallyprovided to a bottom one of the walls to form a chamber or cavity tohold the volume of water.

The reservoir base 6112 is structured and arranged to engage orinterface with the reservoir lid 6114. In an example as shown in FIG.19C, the perimeter of the reservoir base 6112 provides surfaces arrangedto engage or interface with a seal 6116 provided to the reservoir lid6114, e.g., to prevent egress of water from the water reservoir.

The reservoir base 6112 may be structured and arranged to retain thereservoir lid 6114 to the reservoir base 6112, e.g., hinge arrangementand/or snap-fit locking tabs to releasably retain the reservoir lid tothe reservoir base.

Conductive Portion

The conductive portion 6150 is configured to allow efficient transfer ofheat from a heating element (e.g., heater plate 6080 of the reservoirdock 6050 shown in FIG. 6B) to the volume of liquid in the reservoir. Inone form, the conductive portion may be arranged as a plate, althoughother shapes may also be suitable. All or a part of the conductiveportion may be made of a thermally conductive material such as aluminium(e.g. approximately 2 mm thick, such as 1 mm, 1.5 mm, 2.5 mm or 3 mm),another heat conducting metal or some plastics. In some cases, suitableheat conductivity may be achieved with less conductive materials ofsuitable geometry.

Conductive Portion Including Metal Plate and/or Thin Film

In an example, the conductive portion 6150 may comprise a metal plate, athin, non-metallic film (also referred to as a film plate or film base),or a combined layered arrangement of a metal plate and a thin,non-metallic film. As described below, the conductive portion 6150 isconfigured to thermally couple with the heater plate 6080 of thereservoir dock 6050 so as to allow thermal transfer of heat from theheater plate 6080 to the volume of liquid in the water reservoir 6100.

FIGS. 10A to 10G show a reservoir base 6112M1 comprising a metal plateas the conductive portion 6150M according to an example of the presenttechnology. In an example, the reservoir base 6112M1 comprises atwo-part construction, i.e., only a main body 6140 and a metalconductive portion 6150M.

As illustrated, the main body 6140 comprises a plurality of walls andthe metal conductive portion 6150M is provided to a bottom one of thewalls to form the chamber to hold the volume of water. For example, themain body 6140 includes side walls 6142 extending around the perimeterof the main body 6140 and a bottom wall 6144 that joins the side walls6142. The metal conductive portion 6150M is provided or otherwiseincorporated into the bottom wall 6144 to form the chamber for holdingwater.

In an example, the metal thermo-conductive portion 6150M is provided asa separate and distinct structure from the main body 6140 and thensecured or otherwise provided to the bottom wall 6144 in an operativeposition, e.g., the metal conductive portion 6150M comprises apre-formed structure that is secured to the bottom wall 6144. In anexample, the metal conductive portion 6150M comprises a metallicmaterial, e.g., metal plate, and the main body 6140 comprises a plasticor thermoplastic polymer material, e.g., PC, ABS, copolyester. In anexample, the conducive portion 6150M generally may have a uniform wallthickness of about 0.25-0.50 mm, e.g., 0.40 mm. For metal conductiveportions, the wall thickness can be even larger, e.g., up to 1.5 mm. Ifa thin film is used instead (see description below regarding FIGS. 13Ato 13C), a smaller thickness, such as 0.1-0.5 mm may be used.

In an example, the metal conductive portion 6150M may be pre-formed, andthen insert molded to the plastic main body 6140. For example, the metalconductive portion is first formed into its working configuration by oneor more metal-forming processes. The metal conductive portion or insertis then inserted into an injection mold for the main body prior to meltinjection. During the injection process, the melt flows around the edgesof the metal conductive portion and locks or connects the metalconductive portion to the main body as the melt solidifies.

As illustrated in FIG. 10G, the metal conductive portion 6150M mayinclude a bottom wall or plate 6152M, a side wall 6154M extending aroundthe perimeter of the plate 6152M, and an interfacing portion 6156Mengaging with bottom wall 6144 to secure the metal conductive portion6150M to the plastic main body 6140. In an alternative arrangement, themetal conductive portion 6150M may extend up to the peripheral sidewalls 6142 of the main body 6140, thus replacing the bottom wall 6144.In this case, interfacing portion 6156M may engage the side walls 6142of the main body 6140.

As illustrated in FIG. 10G, the plate 6152M includes a first side6152.1M adapted to form a bottom interior surface of the reservoir, thesurface of the first side being exposed to the water. The second side6152.2M of plate 6152M is opposite to the first side and is adapted toform a bottom exterior surface of the reservoir, which surface isexposed to the heater plate. Thus, the second side 6152.2M of the plateprovides a contact surface structured and arranged to directly engagewith the heater plate 6080.

In an example, the plate 6152M may comprise a pre-formed curvature ordome-shape, i.e., the second side 6152.2M provides a generally convexsurface. When the water reservoir 6100 is inserted into the reservoirdock 6050, a bias may be provided between the water reservoir and theheater plate so that the curved plate 6152M will flatten, e.g., becomesubstantially planar, so as to align or conform itself with the flatsurface of the heater plate 6080. The flattening of the curved plate6152M creates a bias between the plate 6152M and the heater plate 6080to ensure good thermal contact and improve heat transfer between theheater plate and water within the water reservoir. In an example, thecurvature of the plate may be formed by placing the metal conductiveportion into a smaller opening in the bottom wall of the main body,e.g., smaller opening in the bottom wall compresses the metal conductiveportion to form curvature in the plate.

In an alternative example, the plate 6152M may comprise a generallyplanar shape, i.e., pre-formed planar shape.

In the illustrated example, the metal conductive portion 6150M isconfigured such that the plane of plate 6152M is offset and generallyparallel to the plane of bottom wall 6144 of the main body 6140, i.e.,plate is inferior the bottom wall in the operational verticalorientation of the water reservoir. In an alternative example, the metalplate 6152M may be configured such that the plate is generally co-planarwith the bottom wall 6144, i.e., thereby providing the reservoir basewith substantially flat bottom surface. In another example, the metalplate 6152M may be configured to extend in more than one plane, e.g.,the metal plate may provide a stepped arrangement as shown in FIG. 29.

In an example, the metal conductive portion 6150M may include a surfacetreatment, e.g., plasma surface treatment. For example, interior and/orexterior sides of the metal conductive portion, e.g., at least on itsinterfacing portion 6156M, may comprise nano-plasma particles on themetal surface.

In the illustrated example, the plate 6152M of the reservoir base 6112M1includes a rectangular shape, e.g., corresponding to a shape of theheater plate 6080 within the reservoir dock 6050. However, it should beappreciated that the plate 6152M may comprise other suitable shapes,which may or may not correspond to a shape of the heater plate, e.g.,circular, square, oval. For example, FIGS. 11A to 11C illustrate areservoir base 6112M2 in which the metal plate 6152M of the metalconductive portion 6150M is circular. In alternative examples, the sidewall extending around the perimeter of the plate and/or the interfacingportion may be longer to provide a deeper drawn metal conductiveportion, e.g., see FIGS. 12A to 12C showing a reservoir base 6112M3 witha deeper drawn, rectangular-shaped, metal conductive portion 6150M.

FIGS. 13A to 13C show a reservoir base 6112F1 comprising a thin,non-metallic film as the conductive portion 6150F according to anexample of the present technology. In an example, the reservoir base6112F1 comprises a two-part construction, i.e., only a main body 6140and a thin film conductive portion 6150F.

The thin film conductive portion 6150F can comprise a thermallyconductive, non-metallic material, e.g., silicone, polycarbonate, orother thermoplastic or elastomeric materials, e.g., copolyester.

In an example, the thin film conductive portion 6150F may comprise athickness of about 0.05 mm to 0.5 mm, e.g., 0.10 mm to 0.125 mm. In rarecases, thicker films, i.e., up to 1.5 mm, may be required. In anexample, the thin film conductive portion 6150F may comprise a thicknessequal or less than about 1 mm, e.g., 0.5 mm, less than about 0.5 mm,e.g., 0.40 mm, 0.375 mm, 0.25 mm, 0.175 mm, 0.125 mm.

As shown in FIGS. 13A to 13C, the main body 6140 of the reservoir base6112F1 includes a bottom wall 6144 and side walls 6142 extending aroundthe perimeter of the bottom wall 6144. In such an example, the thin filmconductive portion 6150F can extend across a hole provided to the bottomwall 6144, and the thin film conductive portion 6150F is provided notonly across the hole, but also over at least a portion of the remainingbottom wall 6144 to enhance the seal between them and ensure that thereservoir base does not leak water. The thin film conductive portion6150F thus forms at least a portion of the bottom of the reservoir baseto form the chamber to hold and prevent egress of water from the waterreservoir. Also, e.g., for a better seal, the thin film conductiveportion 6150F may not only overlap the opening in the bottom wall 6144but also extend to cover at least portions of the side walls 6142 of thereservoir base.

In an example, the thin film conductive portion 6150F is provided as aseparate and distinct structure from the main body 6140 and then securedor otherwise provided to the main body in an operative position, e.g.,the thin film comprises a pre-formed structure that is secured to themain body. In an example, the main body 6140 comprises a plastic orthermoplastic polymer material, e.g., PC, ABS, copolyester.

In an example, the thin film conductive portion 6150F may be pre-formed,and then insert molded or otherwise attached (e.g., by using adhesive)to the plastic main body 6140. For example, the thin film conductiveportion 6150F is first formed into its working configuration, e.g., by avacuum forming process. The thin film conductive portion 6150F or insertmay then be insert molded to the plastic main body 6140. A reference isprovided to application WO 2018/094452, which is hereby incorporated byreference in its entirety.

Post-Molding Forming of Thin Film

When insert-moulding a thin film plate into a polycarbonatehumidification tub base (also referred to as a water reservoir base),there may be problems with the geometry of the film. Usually, the filmis preformed (e.g., stamped into a deep drawn step-wise shape) and theninsert-moulded. However, when the mould cools down, tension in variouslocation within the mould may lead to the film bending and distorting.This is further complicated by the fact that the thin film and the waterreservoir base have different mechanical characteristics and coefficientof thermal expansion/shrinkage. Because of this, the film shape isdifficult to control during the cooling process. One way to mitigatethis problem is the following. Instead of pre-forming, forming the shapeof the film after the moulding process (post-mould forming). This is tosay that one can insert-mould the film as a flat film and post-form itinto its drawn shape afterwards. It will still shrink during themoulding. However, when the shrinked/distorted film is post-formed—theforming process will tighten/straighten the film, allowing a tightergeometry control.

In the post-mould forming process, one starts with a film in some form(say a flat film). The film is a non-final form (say a flatconfiguration). The plastic can then be insert moulded around the flatfilm. After the plastic moulding, the film is again distorted. However,one can now use stamping, vacuum forming or thermal vacuum forming—inorder to create a desired step-wise geometric shape. During theformation of this final geometry of the film, the film is stretched in acontrolled way, allowing the formation of a very flat surface.

The process of vacuum forming is similar to that of moulding, since itusually involves temperature and pressure, although for some smallgeometry changes, pressure alone may be sufficient. For a good geometrycontrol we need a good temperature control. For that purpose, during thestep-wise geometry formation, we soften the film only and try not tosoften the plastic tub surface around the film. Therefore, the chemicalcompositions of the tub and the film, the temperature and pressure forthe post-forming, should be such that during the post-mould formingprocess only the film is softened, and not the tub. The shape does nothave to be step wise—it can be any surface that has one or more dimples(tensioning region) that take the looseness out of the flat surface.

The technology can also be used in the manufacture of masks, LCD windows(for thin film coverage with antibacterial properties (the film willcover any gaps, edges that can collect bioburden). In one example, filmcan be used for manufacturing masks, i.e., for a disposable mask. A thinfilm is probably most suitable for forming the walls defining the plenumchamber of the mask. However, frames can also include a thin film body,with only the edges being formed of more rigid plastic attached to theseal. The geometry in a mask may be much more complex, e.g., tightcontrol may be important. This can be done by post-forming. It isimportant to ensure a homogeneous junction between the film and theremaining surface.

When we require the processing of the thin film to be performedpost-molding, there is a certain time that needs to pass after theprocess of moulding, in order for the film to be efficiently performed.This time may be relevant to the cooling of the moulded film, and/or thestage of the process of shrinkage associated with the cooling process.These two processes (the cooling and the shrinkage) are bothnon-linearly dependent on time and, whilst closely related, are stilldifferent processes. This is one clear advantage of the proposedprocess, which allows the film forming process to be performed in thesame tool and setup as the insert-moulding process. This can bringsubstantial time and cost savings.

For a successful post-moulding forming of a thin film, it is importantto follow a process that allows any significant dimensional change (suchas one that occurs during the moulding of the plastic over the film) tostabilise, before the film formation. The intent is for the post formingto be completed at a stage where a sufficient cooling has alreadyoccurred so that the plastic is approaching dimensional stability. Thusa post-moulding forming may allow good dimensional control anddimensional stability of the formed thin film component.

Also—the process is suitable to anywhere where there is a window/openingin the part. The window allows the stamping tool to access the film andperform the post-mould forming step. An arrangement with a plurality ofwindows are used with a one or more large film portions, one or more ofthem arranged to cover more than one of the windows.

As illustrated in FIG. 13C, the thin film conductive portion 6150Fincludes a bottom wall or plate 6152F, a side wall 6154F extendingaround the perimeter of the plate 6152F, and an interfacing portion6156F to secure the thin film conductive portion 6150F to the plasticmain body 6140.

As illustrated in FIG. 13C, the plate 6152F includes a first side6152.1F adapted to form a bottom interior surface of the reservoir,which surface is exposed to the water. The plate 6152F includes a secondside 6152.2F, opposite to the first side, and, in some cases, adapted toform a bottom exterior surface of the reservoir, which surface isexposed to the heater plate. Thus, the second side 6152.2F of the plateprovides a contact surface structured and arranged to directly engagewith the heater plate 6080.

In an example, similar to a previous example described in relation to ametal thermo-conductive plate, the 6152F plate may comprise a pre-formedcurvature or dome-shape, i.e., the second side 6152.2F provides agenerally convex surface. When the water reservoir 6100 is inserted intothe reservoir dock 6050, the water reservoir and the heater plate may bebiased against each other so that the curved plate 6152F will flatten,e.g., become substantially planar, so as to align or conform itself withthe flat surface of the heater plate 6080. The flattening of the curvedplate 6152F creates a bias between the plate 6152F and the heater plate6080 to ensure good thermal contact and improve heat transfer betweenthe heater plate and water within the water reservoir. In an example,the curvature of the plate may be formed by placing the thin filmconductive portion into a smaller opening in the bottom wall of the mainbody, e.g., smaller opening in the bottom wall compresses the thin filmconductive portion to form curvature in the plate.

In an alternative example, the plate 6152F may comprise a generallyplanar shape, i.e., pre-formed planar shape.

In the illustrated example, the thin film conductive portion 6150F isconfigured such that the plate 6152F is offset and generally parallel tothe bottom wall 6144 of the main body 6140, i.e., plate is inferior thebottom wall. In an alternative example, the thin film conductive portion6150F may be configured such that the plate 6152F is generally co-planarwith the bottom wall 6144, i.e., thereby providing the reservoir basewith substantially flat bottom surface. In another example, the thinfilm conductive portion 6152F may be configured to extend in more thanone plane, e.g., the thin film conductive portion may provide a steppedarrangement as shown in FIG. 29.

In an example, not shown, one or more ribs may be provided along thefirst side and/or second side of the thin film conductive portion 6150F,e.g., to add rigidity to the thin film conductive portion and/or toenhance force adapted to push the thin film conductive portion towardsthe heater plate.

In an example, a thin metallic layer (e.g., mesh) may be provided alongthe first side and/or second side of the thin film conductive portion6150F, e.g., to improve thermal conductivity.

In the illustrated example, the plate 6152F of the reservoir base 6112F1includes a rectangular shape, e.g., corresponding to a shape of theheater plate 6080 within the reservoir dock 6050. However, it should beappreciated that the plate 6152F may comprise other suitable shapes,which may or may not correspond to a shape of the heater plate, e.g.,circular, square, oval. For example, FIGS. 14A to 14C illustrate areservoir base 6112F2 in which the plate 6152F of the thin filmconductive portion 6150F is circular.

FIGS. 15A to 15C show a reservoir base 6112MF1 comprising a combinedlayered arrangement of a metal plate and a thin, non-metallic film asthe conductive portion 6150MF according to an example of the presenttechnology. In an example, the reservoir base 6112MF1 comprises athree-part construction, i.e., a main body 6140, a metal conductiveportion 6150M, and a thin film conductive portion 6150F.

The thin film conductive portion 6150F can comprise a thermallyconductive, non-metallic material, e.g., silicone, polycarbonate, orother thermoplastic or elastomeric materials, e.g., copolyester.

In an example, the thin film conductive portion 6150F may comprise athickness of about 0.05 mm to 1 mm, e.g., 0.10 mm to 0.125 mm. In anexample, the thin film may comprise a thickness less than about 1 mm,e.g., 0.5 mm, less than about 0.5 mm, e.g., 0.40 mm, 0.375 mm, 0.25 mm,0.175 mm, 0.125 mm.

In an example as shown in FIGS. 15B and 15C, the reservoir base 6112MF1includes a bottom wall 6144 and side walls 6142 extending around theperimeter of the bottom wall 6144. In such an example, the thin filmconductive portion 6150F not only covers the metal conductive portion6150M, but also extends over at least a portion of the remaining bottomwall 6144. Such arrangement ensures that the connecting boundary betweenthe metal conductive portion 6150M and the bottom wall 6144 is coveredby the thin film conductive portion 6150F to enhance the water sealbetween them and ensure that the reservoir base does not leak water. Fora better seal, the thin film conductive portion 6150F may not only coverthe connecting boundary between the metal conductive portion 6150M andthe bottom wall 6144, but also extend to cover at least portions of theside walls 6142 of the reservoir base. This is especially important inthe case where the metal conductive portion 6150M covers the entirebottom wall 6144 and, possibly part of the side wall 6142, and theconnecting boundary is actually between the metal conductive portion6150M and the side wall 6142.

As illustrated, the thin film conductive portion 6150F includes a firstside 6152.1F adapted to form a bottom interior surface of the reservoir,which surface is exposed to the water. The thin film conductive portion6150F includes a second side 6152.2F, opposite to the first side,adapted to engage the metal conductive portion 6150M and bottom and sidewalls 6144, 6142 of the reservoir base. The metal conductive portion6150M forms a bottom exterior surface of the reservoir, which surface isexposed to the heater plate 6080. Thus, the metal conductive portion6150M provides a contact surface structured and arranged to directlyengage with the heater plate 6080. One advantage of such an arrangementis that the metal thermo-conductive plate 6150M, which is much morescratch resistant, is the one exposed to the mechanical interaction withthe heater plate 6080.

In an alternative example (not shown), the thin film conductive portion6150F may be disposed on the other, external surface of the reservoir,with the metal conductive portion 6150M forming the inner (superior)surface that is on contact with the water content of the reservoir. Anadvantage of such an arrangement may be in that the chemical compositionand stability of the thin film conductive portion in this case is lesscritical, e.g., the thin film conductive portion is not into contactwith the water in the reservoir.

In an example, one or more ribs may be provided along the first sideand/or second side of the thin film conductive portion 6150F, e.g., toadd rigidity to the thin film and/or to enhance force adapted to pushthe thin film/metal plate towards the heater plate.

In an example, a metallic layer (e.g., mesh) may be provided along thefirst side and/or second side of the thin film conductive portion 6150F,e.g., to improve thermal conductivity.

In an example, the conductive portion 6150MF may include a shapecorresponding to a shape of the heater plate 6080, e.g., for stability,more efficient thermal conductivity. For example, the conductive portion6150MF and heater plate 6080 may include circular or non-circularshapes, e.g., rectangular, square, oval. In illustrated example, theconductive portion 6150MF includes a rectangular shape, e.g.,corresponding to a shape of the heater plate 6080 within the reservoirdock 6050. FIGS. 16A to 16C show an alternative example in whichreservoir base 6112MF2 includes a circular, conductive portion 6150MF.FIGS. 17A to 17C show a reservoir base 6112MF3 including a deeper drawn,rectangular-shaped, conductive portion 6150MF.

In an example, the thin film conductive portion 6150F and the metalconductive portion 6150M are provided as separate and distinctstructures from the main body 6140 and then secured or otherwiseprovided to the main body 6140 in an operative position, e.g., the thinfilm conductive portion 6150F and the metal conductive portion 6150Fcomprise pre-formed structures that are secured to the main body 6140.In an example, the main body 6140 comprises a plastic or thermoplasticpolymer material, e.g., PC, ABS, copolyester.

In an example, the thin film conductive portion 6150F may be pre-formed(e.g., vacuum formed), and then assembled to a pre-formed metalconductive portion 6150M (e.g., bonded, laminated, or simply engagedwith one another). Then, the thin film/metal plate heat conductingassembly portion may be insert molded to the plastic main body 6140,i.e., bottom and side walls of main body 6140 injection molded to thethin film/metal plate assembly. In another example, the metal conductiveportion 6150M can be separately insert molded to the main body 6140 andthen the thin film conductive portion 6150F may be bonded to the metalconductive portion 6150M so as to cover at least the metal conductiveportion 6150M, and preferably areas of the main body 6140 beyond themetal conductive portion 6150M, so as to ensure a reliable sealing ofthe contact boundary between the metal conductive portion 6150M with themain body 6140. Vacuum may be used to remove any air gap between thethin film conductive portion 6150F and metal conductive portion 6150M inany of the above examples. Also, bonding, e.g., adhesive, may be usedbetween the thin film conductive portion 6150F and metal conductiveportion 6150M, e.g., to maintain assembly and ensure good thermalconductivity.

In an example, the metal conductive portion 6150M and/or thin filmconductive portion 6150F may comprise a pre-formed curvature ordome-shape, i.e., the inferior side of the metal conductive portion6150M and/or thin film conductive portion 6150F provides a generallyconvex surface. When the water reservoir 6100 is inserted into thereservoir dock 6050, the curved metal plate/thin film will flatten,e.g., become substantially planar, so as to align or conform itself withthe flat surface of the heater plate 6080. The flattening of the curvedmetal plate/thin film creates a bias between the metal plate/thin filmand the heater plate to ensure good thermal contact and improve heattransfer between the heater plate and water within the water reservoir.In an example, the curvature of the metal plate/thin film may be formedby placing the metal plate/thin film into a smaller opening in thebottom wall of the main body, e.g., smaller opening in the bottom wallcompresses the metal plate/thin film to form curvature in the metalplate/thin film.

In an alternative example, the metal plate/thin film may comprise agenerally planar shape, i.e., pre-formed planar shape.

In the illustrated example, the metal plate/thin film is configured suchthat the metal plate/thin film is offset and generally parallel to thebottom wall of the main body, i.e., metal plate/thin film is inferiorthe bottom wall. In an alternative example, the metal plate/thin filmmay be configured such that the metal plate/thin film is generallyco-planar with the bottom wall, i.e., thereby providing the reservoirbase with substantially flat bottom surface. In another example, themetal plate/thin film may be configured to extend in more than oneplane, e.g., the metal plate/thin film may provide a stepped arrangementas shown in FIG. 29.

The combination of the thin film conductive portion 6150F and the metalconductive portion 6150M may be advantageous in that the non-metallicproperties of the thin film (e.g., thermoplastic or elastomeric materialproperties) provides corrosion protection (e.g., protection due toexposure to water) and an improved seal with the bottom wall (e.g., toform a sealed reservoir for the humidification water), while themetallic properties of the metal plate provide good thermal contact,rigidity, and durability, e.g., for multi-patient multi-useapplications.

Reservoir Lid

As shown in FIGS. 18A, 18B, and 19A to 19G, the reservoir lid 6114 isconfigured to connect to the reservoir base 6112. The configuration maybe arranged to allow the water reservoir to be convertible between anopen configuration and a closed configuration. For example, thereservoir lid 6114 may be hingedly connected to the reservoir base 6112by hinge pins. In an alternative example, the reservoir lid 6114 mayinclude a plurality of resilient locking tabs adapted to interlock withthe reservoir base 6112, e.g., with a snap-fit. In an example, a seal6116 (e.g., see FIG. 19C) may be provided to the reservoir lid 6114,e.g., to prevent egress of water from the connecting boundary betweenthe lid 6114 and the base 6112 of the water reservoir. In one form, thereservoir lid 6114 may be constructed from a bio-compatible material,such as a plastic or thermoplastic polymer, e.g., PC, ABS, copolyester,etc.

As shown in FIGS. 18A and 18B, the reservoir lid 6114 may comprise aninlet tube 6120 arranged to provide an inlet for receiving the flow ofair into the water reservoir, and an outlet tube 6130 arranged toprovide an outlet for delivering a flow of humidified air from the waterreservoir.

When the reservoir lid 6114 is coupled to the reservoir base 6112, theinlet tube 6120 includes an outer (inlet) end 6124 arranged outside thechamber and an inner (outlet) end 6126 arranged inside the chamber.Likewise, the outlet tube 6130 includes an outer (outlet) end 6134arranged outside the chamber and an inner (inlet) end 6136 arrangedinside the chamber. Each of the inlet tube or the outlet tube (togetherwith each tube's respective inlet and outlet) may be replaced by anopening in a wall of the reservoir lid.

In an example, an inlet seal 6122 is provided to the free outer (inlet)end of the inlet tube 6120 (see FIGS. 19A, 19B, 19D, and 21), and/or anoutlet seal 6132 is provided to the free outer (outlet) end of theoutlet tube 6130 (e.g., see FIG. 21). The fact that the inlet and outletseals 6122, 6132 are a part of the water reservoir and not, say of theRPT device, allows seal replacement each time the water reservoir isreplaced, i.e., which is useful feature, especially in the case of adisposable water reservoir. In an example, each seal comprisesbellows-type arrangement that may provide a certain degree of decouplingbetween the two connecting parts. In an example, the inlet seal andoutlet seal may be overmolded to the reservoir lid.

FIG. 80 illustrate an integrated RPT device and humidifier 6000according to an example of the present technology similar to thatillustrated in FIGS. 6A, 6B, 7 and 8A to 8D.

FIGS. 80, 85, 86 and 134-136 show a water reservoir 6100 and a reservoirlid 6114 according to another example of the present technology. In thisexample, an inlet seal 6122 (e.g., bellows-type arrangement) is providedto the free outer (inlet) end of the inlet tube 6120, while no seal isprovided to the free outer (outlet) end of the outlet tube 6130. Asdiscussed later in the text, instead, such a seal may be provided to theinlet of the intermediate element to which the outlet tube 6130 isattached. In use, when the water reservoir 6100 is removably coupledwith the reservoir dock 6050, the inlet seal 6122 of the inlet tube 6120(or inlet) of the water reservoir 6100 is structured and arranged toprovide a face seal with the chassis outlet 7320 (dock inlet) of thereservoir dock 6050 (see FIGS. 100, 131 and 133), and the inlet seal9715 of the intermediate component 9700 (described in greater detailbelow) is structured and arranged to provide a face seal with the outletend of the outlet tube 6130 (or outlet) of the water reservoir 6100 (seeFIGS. 131 and 132).

Also, in this example, the inlet seal 6122 may be overmolded to thereservoir lid 6114 along with the peripheral seal 6116 arranged to forma seal between the lid 6114 and the base 6112 in use (see FIG. 85),e.g., seals 6122, 6116 from integral, once-piece component ofelastomeric material. That is, as shown in FIG. 85, the reservoir lid6114 (including the inlet tube 6120 and the outlet tube 6130) maycomprise a first part or base mold constructed of a relatively rigidmaterial (e.g., thermoplastic polymer (e.g., PC, ABS)) and the inletseal 6122 and the seal 6116 may comprise a second part or overmoldconstructed of a relatively soft material (e.g., thermoplastic elastomer(TPE) or silicone) that is provided (e.g., by overmolding) to the firstpart.

Further, as shown in 80 and 85, a thumb grip 6133 may be provided (e.g.,mechanical interlock, snap-fit) to the top of the reservoir lid 6144 tofacilitate manual manipulation of the water reservoir 6100 and/orinterlocking of the water reservoir 6100 with the reservoir dock 6050.The thumb grip helps to align the reservoir 6100 upon insertion. It alsofacilitates gripping and squeezing the portion of the reservoir 6100which extends outside of the RPT device and humidifier 6000 (e.g., seeFIG. 79). Because of the deforming nature of the peripheral seal 6116,upon the user depressing the thumb grip (squeezing the reservoir 6100),the seal yields and reduces the transverse dimension of the waterreservoir 6100. This reduces the friction during insertion or extractionof the water reservoir 6100 into/from the humidification dock, thusimproving the overall user experience.

Spillback Protection

In an example, the water reservoir 6100 may be configured to discourageegress of liquid therefrom, such as when the water reservoir isdisplaced and/or rotated from its normal, working orientation.

In an example, as shown in FIGS. 19C to 19G, the inlet tube 6120 caninclude an outer (inlet) end 6124 arranged outside the chamber and aninner (outlet) end 6126 arranged inside the chamber. The inlet tube 6120includes an inlet portion 6123 including the inlet end 6124 and anoutlet portion 6125 including the outlet end 6126. The bottom of thewater reservoir (e.g., the conductive portion 6150) includes a bottomsurface defining a bottom plane that is substantially horizontal whenthe water reservoir is in the normal, working orientation (e.g., seeFIG. 19C). As illustrated in FIGS. 19C to 19G, various portions of theinlet tube 6120 may extend in different directions, e.g., changedirection at least at one point along its length. For example, the inletportion 6123 extends in a plane that is substantially parallel to thebottom plane, while the outlet portion 6125 extends in a differentdirection (in this case the outlet portion 6125 extends in a plane thatis substantially perpendicular to the bottom plane). Various twistsand/or turns may be introduced in each portion (orientation) of theinlet tube 6120.

As shown in FIGS. 19C to 19G, the outlet tube 6130 can include an outer(outlet) end 6134 arranged outside the chamber and an inner (inlet) end6136 arranged inside the chamber. Similar to the inlet tube, the outlettube can also extend in different directions, e.g., change direction atleast at one point along its length. Also similar, the outlet tube 6130can include a vertical twist (a bend in the plane that is substantiallyperpendicular to the bottom plane) such that the outlet tube 6130 curvesdownwardly from the outlet end 6134 to the inlet end 6136, which allowsthe outlet tube 6130 to cross under the inlet portion 6123 of the inlettube 6120. Further, the opening at the inlet end 6136 of the outlet tube6130 is curved upwards to prevent spitting (which happens when water ispushed out of the outlet tube due to pressure and flow).

FIGS. 19D, 19H-1, 19H2, and 19I show a change in direction of the inletand outlet tubes in the horizontal plane, while FIGS. 19C, 19E, and 19Fshow similar turns in vertical direction (the respective tubeeffectively moving closer to, or further away from, the bottom surfaceprovided by the conductive portion 6150).

In an example, the outlet end 6126 of the inlet tube 6120 and the inletend 6136 of the outlet tube 6130 may be arranged at or near thegeometric center or centroid of the reservoir chamber.

The inlet tube 6120 and the outlet tube 6130 could be further arrangedsuch that at least one (and preferably at least two) of:

a. the outer (inlet) end 6124 of the inlet tube 6120;

b. the inner (outlet) end 6126 of the inlet tube 6120;

c. the outer (outlet) end 6134 of the outlet tube 6130; and

d. the inner (inlet) end 6136 of the outlet tube 6130,

is above a level of the predetermined maximum volume of water both when:(1) the water reservoir is in the working orientation and (2) the waterreservoir is rotated by 90 degrees in at least one direction from theworking orientation.

Depending on the arrangement and the horizontal and vertical location ofthe above mentioned inlets/outlets, in some examples the same at leastone (or two) inlets/outlets will be elevated above the water level whenthe reservoir is turned at 90 degrees. In other arrangement, at leastone (or two) inlets/outlets will be elevated above the water level inthe operational configuration, while the other at least one (or two)inlets/outlets will be elevated above water when the reservoir is tiltedat 90 degrees.

For example, FIG. 19C shows inlet end 6124, outlet end 6126, outlet end6134 and inlet end 6136 all above the water level in the workingorientation, FIG. 19D shows outlet end 6126 and outlet end 6134 abovethe water level when the water reservoir is rotated by 90 degrees front,and FIG. 19D shows inlet end 6124 and inlet end 6136 above the waterlevel when the water reservoir is rotated by 90 degrees back. Also, FIG.19G shows at least the outlet end 6126 above the water level when thewater reservoir is rotated by 180 degrees. Such arrangement achievesspillback protection to discourage water from entering the inlet andoutlet tubes of the water reservoir at various orientations. Inaddition, as shown in FIGS. 19C and 19I, in the operationalconfiguration, the inlet tube 6120 is inclined so that its inlet 6124 ishigher than its outlet end 6126. Because of that, when the waterreservoir is returned to its operational configuration, after it hasbeen filled in (and in the process having being rotated at variousangles, including by at least 90 degrees in any direction), any water inthe inlet tube trickles down back towards the outlet end (the waterchamber) and not the inlet end (which is in the direction of the RPTdevice). This may prevent damage to electronics in the RPT device whenthe water reservoir is received in the reservoir dock.

As described above, the inlet tube 6120 and the outlet tube 6130 for thewater reservoir can be curved and extend in different directions, e.g.,curved in one or more planes. The curved tubes 6120, 6130 can allow morecontrol and flexibility in positioning the tube inlets and outlets at apreferred location within the water reservoir, i.e., to improve thewater spill protection of the tub. The curved tubes 6120, 6130 can allowfor a better utilization of the space in the water reservoir and betterintegration of all reservoir elements as one whole, as well as for moreflexibility in defining airlock features of the reservoir. In anexample, the inlet tube 6120 and/or the outlet tube 6130 may also changeits diameter along its length (e.g., see FIG. 19D), e.g., to provideflexibility to locate the tubes in the water reservoir.

As described above, the spillback feature involves the inlet and outlettubes 6120, 6130 having their outlet end 6126/inlet end 6136 beinglocated in the middle of the water reservoir (e.g., at or near thegeometric center or centroid of the reservoir chamber), so that upon anaccidental tumbling of the water reservoir in various angles, when thewater reservoir still includes a certain amount of water, the level ofthat water stays mostly below the level of these centrally locatedoutlet end 6126/inlet end 6136 of the inlet and outlet tubes 6120, 6130.This is where the curved shape of the tubes can help. In particular, ifone of the tubes is directed so that its outlet end 6126/inlet end 6136is located centrally to the water reservoir, the other tube may notsimply extend below the first tube (and therefore move away from thecentral area of the water reservoir), but can be directed to bend belowthe first tube and then curve back to any desired level.

In alternative designs, the tubes may simply cross each other atdifferent levels. Such a design can define two sides of the reservoirfor which, when the reservoir is tilted on one of these sides, one ofthe inlet or the outlet tube is inclined upwardly, thus keeping therespective in-tub opening above the water level. In this case the othertube would be inclined downwardly and the in-tub opening may be exposedto the water, unless mitigation measures have been taken. The curveddesign of the present technology may mitigate this problem.

The curvature of the inlet tube 6120 and/or the outlet tube 6130 may bea shallow or a significant curvature. The curvature can also be in morethan one plane, in order to optimize the inner space of the tub. Theconcept of curving the tubes may be further enhanced by introducing asecond curvature, subsequent to the first one, which may change thedirection, or at least the radius, of the first curvature. The premisebehind such shapes is that they can introduce further resistance to apropagation of water in some direction. Thus, such consecutive “kinks”that extend in one or more planes/directions, can provide resistance inthe respective one or more directions, and therefore protect againsttumbling/rolling over/flipping of the reservoir. Of course, the benefitcan be weighed against the complexity of the design and the resistanceprovided to the airflow.

Thus, curved tubes inside the reservoir may allow for an improved waterspillage feature of the reservoir and better utilized space. This mayallow for the reservoir to be internally optimized and the overallvolume of the reservoir to be reduced. The improved overall efficiencyallows to either fit more water or reduce the overall size of thereservoir. Instead of introducing a continuous curvature, similarresults may also be achieved with the tube changing direction, at thedesired point along its length, by way of a discrete angle.

In an example, the inlet tube 6120 and/or the outlet tube 6130 may beprovided as a separate and distinct structure from the reservoir lid6114 (e.g., see FIGS. 19H-1, 19H-2, and 19I described below) and thensecured or otherwise provided to the reservoir lid 6114 in an operativeposition. Alternatively, the inlet tube 6120 and/or the outlet tube 6130may be formed, e.g., molded, as a part of the reservoir lid 6114 or thereservoir base 6112 (e.g., see FIGS. 134-136 which show the inlet tube6120 and the outlet tube 6130 formed as part of the reservoir lid 6114).In an example, the inlet tube 6120 and/or the outlet tube 6130 maycomprise a different material (e.g., more flexible material) than thereservoir lid, e.g., silicone or TPE to facilitate bending into thedesired configuration. Alternatively, the inlet tube 6120 and/or theoutlet tube 6130 may comprise a similar material to the reservoir lid,e.g., polycarbonate.

For example, FIGS. 19H-1 and 19H-2 show a removable outlet tubearrangement for a water reservoir according to an example of the presenttechnology. As illustrated, the removable outlet tube arrangementincludes the outlet tube 6130 and a portion of the inlet tube 6120,e.g., an outlet end 6126 of the inlet tube 6120. In this example, theinlet portion 6123 and the outlet portion 6125 of the inlet tube 6120may be formed, e.g., molded, as a part of the reservoir lid 6114. Theremovable outlet tube arrangement is formed as a separate and distinctstructure from the reservoir lid 6114 and then secured or otherwiseassembled to the reservoir lid 6114 to form complete inlet and outletair paths. For example, the outlet end 6134 of the outlet tube 6130 issecured or otherwise anchored to a side wall of the reservoir lid 6114and the outlet end 6126 is engaged or otherwise anchored to the end ofthe outlet portion 6125 of the inlet tube 6120. FIGS. 19A to 19G showthe removable outlet tube arrangement secured to the reservoir lid 6114in an operative position.

FIG. 19I shows an alternative example in which the inlet tube 6120 andthe outlet tube 6130 comprise a removable inlet tube and outlet tubearrangement that is a separate and distinct structure from the reservoirlid 6114 and then secured or otherwise provided to the reservoir lid6114 in an operative position.

Hinged Connection of Reservoir Lid to Reservoir Base

FIGS. 82 to 97 show a water reservoir 6100 including reservoir lid 6114hingedly and removably coupled to the reservoir base 6112 according toan example of the present technology.

As illustrated, the water reservoir 6100 comprises a hinge joint betweenthe lid 6114 and the base 6112 which allows the lid 6114 to hingedlymove between an open position (see FIGS. 84 and 89) and a closedposition (see FIGS. 82, 83, and 91).

In the illustrated example, each side of the lid 6114 includes a hingearm 9100 with an inwardly extending hinge pin 9105 (see FIGS. 86 and87). Each hinge pin 9105 is configured to engage with a respectiveopen-ended slot or cavity 9200 provided on each side of the base 6112(see FIGS. 86 and 88).

Each hinge pin 9105 (see FIG. 87) includes a segmented cylindrical shapecomprising a cylindrical surface 9105 c to provide hinged movement, anda flat surface 9105 f—to facilitate engagement/disengagement of eachhinge pin 9105 with/from a respective open-ended slot 9200 (see FIG.88). That is, as shown in FIG. 90, the cross-section of each hinge pin9105 represents a major segment of a circle.

Each open-ended slot 9200 provides a segmented cylindrical surface 9200c to provide hinged movement for a respective hinge pin 9105, and anopen end or side 9200 o providing an opening to facilitate engagementand disengagement of each slot 9200 with the respective hinge pin 9105(see FIG. 88).

As shown in FIGS. 94 and 95, to assemble or engage the lid 6114 with thebase 6112, the lid 6114 is oriented to align each hinge pin 9105 with arespective open-ended slot 9200, and then the lid 6114 is pushed towardsthe base 6112 (e.g., in a generally horizontal direction) until eachhinge pin 9105 is pushed into a respective open-ended slot 9200 (e.g.,with a snap-fit). Because of the flexibility of the opening of the slot9200, the snap-fit engagement can be effected at any orientation of thehinge pin. However, an easier engagement and disengagement of the lid iseffected if, as illustrated in FIG. 95, the flat surface 9105 f of eachhinge pin 9105 is oriented generally horizontally, which allows thesmaller width (or diameter) of the major segment cross-section of thehinge pin 9105, which extends from the flat surface 9105 f to theopposing cylindrical surface 9201 c, to engage with the open end 9200 oof the slot 9200, thereby allowing the hinge pin 9105 to pass relativelyeasy through the open end 9200 o into the interior of the slot 9200.However, the smaller width of the major segment provided by each of thepair of hinge pins is larger than an opening of the open end or side ofthe respective one of the pair of slots, so that even when aligned,force has to be applied to lever the pair of hinge pins out of the pairof slots, by causing each opening to flex out and release a respectiveone of the pair of hinge pins.

Once assembled, the slots 9200 hingedly retain respective hinge pins9105 to allow the lid 6114 to hingedly move between the open position(see FIGS. 89 and 90) and the closed position (see FIGS. 91 and 92).

As shown in FIGS. 82, 91, and 93, the lid 6114 includes a clip 9120adapted to releasably interlock with one or more latches 9220 on thebase 6112, e.g., with a snap-fit, to releasably retain or lock the lid6114 to the base 6112 in the closed position. As illustrated, the clip9120 includes at least one slot 9122, e.g., a pair of slots, adapted toreceive a respective latch 9220. As shown in FIGS. 83 and 93, the freeend of the clip 9120 includes a finger pull tab 9125 that is angledoutwards from the base 6112 to be gripped by the user when the userwants to open the lid by disengaging the clip 9120. As shown in FIG. 93,a small gap G, e.g., 0.2 mm, may be provided between the bottom of eachlatch 9220 and the slot 9122 in clip 9120 in some embodiments, so thatthe latch 9220 is not under constant load when the lid is in the closedand locked position. However, in general, peripheral resilientsupporting member 6096 pushes the lid, and therefore the bottom of eachlatch 9220, upwardly, thus removing any such gaps.

As shown in FIGS. 96 and 97, to disassemble or disengage the lid 6114from the base 6112, the lid 6114 is over-extended or hingedly movedbeyond the fully open position (i.e., further than the rotation stopprovided by the stop member 9110). In the fully open position thesmallest dimension of the segmented cross-section of the hinge pins isgenerally aligned with the opening 9200 o in the respective slots. Whenthe lid is pushed even further back, the stop member 9110 engaged withthe side wall 9210 starts to act as a cantilever and push the hinge pinstowards the opening 9200 o. This causes the opening 9200 o to flex andrelease the hinge pins 9105 out of respective slots 9200. The openings9200 o and the segmented cross-sections of the hinged pins are notstrictly needed, as a continuous push backwards would eventually allowthe stop member 9110 to lever the hinge pins out of the slots 9200, evenwithout the openings or the segmented cross-section. However, having theopenings and having the smaller width or diameter of the major segmentprovided by the hinge pins 9105 arranged at the open end 9200 o of theslot 9200 when the lid 6114 is over-extended, does make thedisengagement of the lid easier, i.e., the flat surface 9105 f of thehinge pin 9105 reduces stress on the hinge when pulling or popping itout of the slot 9200. Also, providing the opening 9200 o changes thelocation of accumulated stress. In particular, upon disengaging the lidby levering the hinge pins out of the slots 9200, stress is generallyconcentrated in the side portions 9100 of the lid. In contrast, when theopenings 9200 o are provided, upon disengaging the lid by levering thehinge pins out of the slots 9200, stress is generally concentrated inthe portion of the tub base that defines the openings 9200 o, as thisportion has to flex and increase the side of the openings, for the hingepins to be released and the lid to be disengaged.

As shown in FIGS. 86 and 97, the lid 6114 includes a stop member 9110adapted to engage a side wall 9210 of the base 6112 when the lid 6114reaches a fully open position, e.g., allows the lid 6114 to rest in thefully open position. In an example, the lid 6114 may be orientedslightly less than 90 degrees from the base 6112 when in the fully openposition, e.g., about 80-90 degrees. In this position, the lid is wellbalanced so that it does not fall forward to close the tub, whilst atthe same time it does not weigh back on the tub so as to tilt itsidewise.

In an alternative example, the positions of the hinge pin 9105 and theslot 9200 may be switched, e.g., the hinge pin 9105 may be provided tothe base 6112 and the slot 9200 may be provided to the lid 6114.

5.6.2.2 Reservoir Dock

In the example illustrated in FIG. 20A, the reservoir dock 6050 isprovided to the chassis assembly 7300 of the RPT device and configuredand arranged to receive the water reservoir 6100. In some arrangements,the reservoir dock 6050 may comprise a locking feature such as a lockinglever or tab, configured to retain the water reservoir 6100 in thereservoir dock 6050.

The reservoir dock 6050 includes a main body forming a cavity to receivethe water reservoir 6100. As best shown in FIGS. 20F and 21, a rear wallof the reservoir dock 6050 comprises the chassis outlet 7320 (alsoreferred to as a dock inlet) structured and arranged to receive apressurized flow of air from the outlet of the RPT device for deliveryto the water reservoir 6100. The reservoir dock 6050 may also include adock outlet 6090 structured and arranged to connect to or otherwiseinterface with either the air delivery tube 4170 or an intermediatecomponent that then connects to the air delivery tube 4170. In anexample of the present technology, the reservoir dock 6050 may allow theair delivery tube 4170 to form a direct, pneumatic connection with thewater reservoir 6100 so that the pressurized flow of air that has beenhumidified in the water reservoir 6100 is delivered directly from thewater reservoir 6100 to the air delivery tube 4170.

The main body of the reservoir dock 6050 comprises a plurality of wallsand a heating element (e.g., heater plate 6080) provided to a bottom oneof the walls to form the cavity to receive the water reservoir 6100.

Water Reservoir to Reservoir Dock Connection

In use, the water reservoir 6100 is removably coupled with the reservoirdock 6050 by inserting the water reservoir 6100 into the reservoir dock6050. In the case where the water reservoir is arranged for directengagement (pneumatic seal) with the air delivery conduit 4170, when thewater reservoir 6100 is coupled to the reservoir dock 6050 (e.g., seeFIG. 21), the inlet seal 6122 of the inlet tube 6120 (or inlet) of thewater reservoir 6100 is structured and arranged to provide a face sealwith the chassis outlet 7320 (dock inlet) of the reservoir dock 6050.Similarly, the outlet seal 6132 of the outlet tube 6130 (or outlet) ofthe water reservoir 6100 is structured to provide a face seal with theair circuit or air delivery tube 4170, e.g., to prevent losses inpneumatic pressure through leak. In the illustrated example, the waterreservoir 6100 is structured and arranged to form a direct, pneumaticseal with the air delivery conduit 4170, completely bypassing the RPTdevice and the reservoir dock 6050. The reservoir dock 6050 facilitatesthis direct connection, but is not part of it. The connections otherthan the pneumatic connection, can be effected between the delivery tubeand the water reservoir dock. For example, the air delivery tube can bestructured and arranged to form a releasable mechanical/lockingconnection and/or an electrical connection with the water reservoirdock. The releasable mechanical (locking) connection can comprise asnap-fit connection.

Removing the RPT device and the reservoir dock 6050 from the airdelivery path eliminates the presence of an internally located couplingcomponent between the water reservoir 6100 and the air delivery conduit4170. This eliminates the need to disassemble and sterilize suchcoupling component, thus making sterilization much easier. In this way,when preparing the device for a different user, the water reservoir 6100is the only component of the RPT device which needs to be replaced orsterilized.

When the water reservoir 6100 is inserted into the reservoir dock 6050and it reaches the operative position, the conductive portion 6150 ofthe water reservoir 6100 aligns with and thermally contacts the heaterplate 6080 of the reservoir dock 6050 to allow heat transfer from theheater plate 6080 to the water in the water reservoir 6100, e.g.,surface of the conductive portion 6150 engages or contacts surface ofthe heater plate 6080. A biasing mechanism may be introduced thatpresses the water reservoir and the heater plate towards each other,thus varying the level of thermal contact between the conductive portionand the heater plate. In one example, a spring element provided to thewater reservoir, the reservoir dock and/or the heater plate may bearranged to bias the water reservoir and the heater plate towards eachother to increase contact pressure and improve thermal contact.

The chassis outlet 7320 (dock inlet), e.g., shown in FIG. 21, isconfigured to receive the pressurized flow of air from the blower of theRPT device, and to pass on the flow of air into the water reservoir 6100via the inlet tube 6120 of the water reservoir 6100. Humidity (i.e.,water vapour) is added to the flow of air as the air travels through thewater reservoir 6100, and the humidified flow of air exits the waterreservoir through the outlet tube 6130. Air flows directly from theoutlet tube 6130 and into the air delivery tube 4170 to deliver the flowof humidified air to the patient.

Guiding Structures for Insertion/Removal

In an example, an outer side portion of the water reservoir 6100provides a dock engagement portion structured and arranged to interfaceand engage a reservoir engagement portion of the reservoir dock 6050. Inan example, the water reservoir 6100 and reservoir dock 6050 may includeguiding structures to facilitate insertion, removal, and alignment ofthe water reservoir 6100 with the reservoir dock 6050.

For example, as shown in FIG. 6B, opposing sides of the water reservoir6100 along the dock engagement portion may include guiding surfaces(e.g. provided by guide rails 6200) arranged to engage correspondingguiding surfaces (e.g., provided by a guide slot 6060) along thereservoir engagement portion of the reservoir dock 6050 to guide thewater reservoir 6100 into the reservoir dock 6050.

In an example, as shown in FIG. 6B, the water reservoir 6100 may beinserted/removed (e.g., by sliding or push/pull only) along a pathextending in a lateral direction (i.e., anterior-posterior direction)into and out of the cavity of the reservoir dock 6050.

In an alternative example, at least a portion of the path forinsertion/removal of the water reservoir may extend in aninferior-superior direction, e.g., at least a portion of the path forinsertion of the water reservoir into the dock includes a slope, such asan elevation or drop down, into the operative position.

For example, the guiding structures of the water reservoir 6100 andreservoir dock 6050 may be structured and arranged to provide an initialhorizontal or sloped insertion of the water reservoir with a subsequentdrop down in the last section into the operative position. In anexample, the reservoir dock may provide a sloping surface with aninternal edge located on the bottom surface of the dock that has to becleared by the water reservoir before it can be dropped down to itsoperative position. The cleared edge and/or the drop down itself mayeffectively lock the water reservoir into the operative position.Further locking features may also be used. Such “push and drop”configuration includes movement of the tub that has components in both ahorizontal and a vertical direction. The optional inclusion of the edgeensures that during insertion of the water reservoir into the reservoirdock, the base of the water reservoir engages a single edge or a smallsurface, as opposed to being dragged over a much larger surface. Thisreduces any wear and potential damage to the heater plate. A springelement may be arranged (e.g., between the reservoir dock and the waterreservoir) to increase contact pressure between the water reservoir andthe heater plate, e.g., to improve thermal contact between the baseplate of the reservoir and the heater plate of the dock.

FIGS. 25A to 27B show a guiding structure to facilitate insertion,removal, and alignment of the water reservoir 6100 with the reservoirdock 6050 according to an example of the present technology. In theillustrated example, the engagement path for insertion/removal of thewater reservoir 6100 extends in an anterior-posterior direction and inan inferior-superior direction, i.e., the engagement path includes bothhorizontal and vertical components.

In the illustrated example, each side of the reservoir dock 6050includes a guide slot 6060 configured to receive a respective guideprotrusion or pin 6250 on each side of the water reservoir 6100. Asillustrated, each guide slot 6060 includes a generally horizontalsection 6060H extending in anterior-posterior direction leading to adrop down section 6060D that slopes downwardly from the generallyhorizontal section 6060H in an inferior direction.

As shown in FIGS. 28A to 28C, the reservoir dock 6050 includes arecessed heating element 6085 configured to engage the conductiveportion 6150 of the water reservoir 6100 so as to allow thermal transferof heat from the heating element 6085 to the volume of liquid in thewater reservoir 6100. As illustrated, the chassis assembly forming thereservoir dock 6050 includes a recessed opening adapted to receive theheating element 6085 (e.g., a heat generating component such as anelectrically resistive heating track). The recessed opening is formed atleast in part by a front ledge 7350 of the chassis assembly at the frontor open end of the reservoir dock 6050 and a rear ledge 7360 of thechassis assembly at the rear or interior of the reservoir dock 6050. Theheating element 6085 is firmly fixed or retained in place via a retainerplate 6095 configured and arranged to sandwich the heating element 6085against the chassis assembly, e.g., against at least the front and rearledges 7350, 7360 of the chassis assembly. In an example, the heatingelement 6085 may comprise a gasket 6086, e.g., silicone bead, along itsperimeter to seal the heating element 6085 within the recessed openingof the chassis assembly.

The conductive portion 6150, e.g., metal plate, of the water reservoir6100 may include a stepped arrangement in which the conductive portion6150 extends in more than one plane. In an example, e.g., see FIG. 29,the conductive portion 6150 includes a first, heat conducting portion6150.1 that extends in a first plane, and a second portion 6150.2 thatextends in a second plane that is offset in a superior direction fromthe first plane. Each of the more than one plane may, but does not haveto, extend in a horizontal plane (with reference to the waterreservoir's operational configuration).

The above recessed configuration of the reservoir dock 6050 and waterreservoir 6100 allows the water reservoir 6100 to drop down onto theheating element 6085 into its operative position. Specifically, theguide pins 6250 of the water reservoir 6100 are engaged withinrespective guide slots 6060 of the reservoir dock 6050 as the waterreservoir 6100 is inserted into the reservoir dock 6050 (e.g., see FIGS.25B and 26A). The generally horizontal section 6060H of the guide slots6060 guide the water reservoir into the reservoir dock, i.e., in ananterior direction. As the water reservoir 6100 is guided along thegenerally horizontal section 6060H of the guide slots 6060, the first,heat conducting portion 6150.1 of the conductive portion 6150 of thewater reservoir 6100 engages and slides along the upper guide surface7355 of the front ledge 7350 supporting the heating element 6085 (e.g.,see FIG. 27A). When the water reservoir 6100 reaches the drop downsection 6060D of the guide slots 6060, the first, heat conductingportion 6150.1 of the water reservoir 6100 also clears the internal edgeof the front ledge 7350, which allows the water reservoir 6100 and thefirst, heat conducting portion 6150.1 thereof to drop down intoengagement with the heating element 6085 (e.g., see FIGS. 25A, 26B, and27B). That is, the stepped arrangement of the conductive portion 6150 ofthe water reservoir 6100 is configured to allow the first, heatconducting portion 6150.1 to drop down into engagement with the recessedheating element 6085 while the second (usually not heat-conducting)portion 6150.2 drops down into engagement with the front ledge 7350(e.g., see FIG. 27B). Such drop down engagement configurationeffectively locks the water reservoir 6100 in an operative position,i.e., the front ledge 7350 provides a guide surface 7355 and also allowsthe water reservoir 6100 to engage therebehind to lock the waterreservoir 6100 in position and prevent unintended release, e.g., duringtreatment, when the entire system is under pressure which may push thewater reservoir out of its operational configuration. In the illustratedexample, the first, heat conducting portion 6150.1 of the waterreservoir 6100 is sized to substantially fill the recessed spaceprovided by the recessed heating element 6085 (e.g., see FIG. 27B),e.g., to prevent any horizontal movement.

As the water reservoir 6100 slides across the front ledge 7350 duringengagement, as opposed to along the heating element 6085, the engagementportion of the bottom surface of the water reservoir 6100, which couldinclude either one or both of the heated plate and the remaining of thebottom wall of the reservoir, engages over a much smaller surface of thebottom of the dock, thus reducing wear and potential damage to the waterreservoir 6110 (i.e., its conductive portion 6150) and the heater plate.Moreover, as the water reservoir 6100 drops down onto the heatingelement 6085 into its operative position, as opposed to sliding acrossthe heating element 6085, in some configurations the heating element6085 may be provided without a heater plate (also referred to as a wearplate or skid plate, e.g., formed of hard metallic material) along itsupper or superior surface to protect the heating element 6085. That is,such engagement configuration allows the conductive portion 6150 of thewater reservoir 6100 to directly engage the heating element 6085 suchthat heat is directly transferred from the heating element 6085 to thevolume of liquid in the water reservoir 6100, i.e., thereby improvingthermal conductivity as heat does not need to pass through a heaterplate or skid plate. Such an arrangement can also be more costeffective.

In the illustrated example of FIGS. 27A and 27B, the upper wall portionof the reservoir dock includes a spring-loaded latch 6300 arranged toincrease contact pressure between the water reservoir 6100 and the fixedheating element 6085, e.g., to improve thermal contact. As illustrated,when the water reservoir 6100 reaches its operative position, thespring-loaded latch 6300 is arranged to resiliently engage the top ofthe water reservoir 6100 to bias the water reservoir 6100 downwards andinto the fixed heating element 6085 (e.g. see FIG. 27B. For removal, thewater reservoir 6100 can be forced against the downwards pressure of thespring-loaded latch 6300 until it reaches the generally horizontalsection 6060H of the guide slots 6060 for removal.

It should be appreciated that downwards force may be provided to thewater reservoir 6100 in other suitable manners. For example, the guideslots of the reservoir dock may include springs or other biasing membersarranged to provide downwards force, e.g., onto the guide pins of thewater reservoir. In another example, the chassis assembly may comprise ahinged lid adjacent the reservoir dock configured to be moved down intoengagement with the water reservoir after insertion of the waterreservoir to provide downwards force. In yet another example, thechassis assembly may comprise a plunger-type element adjacent thereservoir dock configured to be pressed into engagement with the waterreservoir after insertion of the water reservoir to provide downwardsforce.

In an alternative example, the water reservoir 6100 and the reservoirdock 6050 may be arranged such that the water reservoir 6100 can firstdrop down into engagement with the heating element 6085 and then can befurther slid along the heating element 6085 into engagement with thespring-loaded latch 6300. In this example, as shown in FIGS. 30 to 32B,each guide slot 6060 includes an additional, generally horizontalsection 6060H2 extending from the drop down section 6060D. Also, thefirst, heat conducting portion 6150.1 of the conductive portion 6150 ofthe water reservoir 6100 may be reduced in size such that the first,heat conducting portion 6150.1 does not fill the recessed space providedby the recessed heating element 6085, e.g., to allow horizontalmovement. In use, when the water reservoir 6100 reaches the drop downsection 6060D of the guide slots 6060, the first, heat conductingportion 6150.1 of the water reservoir 6100 clears the internal edge ofthe front ledge 7350 and drops down into engagement with the heatingelement 6085. Then, the water reservoir 6100 can be further slid intothe reservoir dock 6050 along the additional, generally horizontalsection 6060H2 until the water reservoir 6100 is slid under and intoengagement with the spring-loaded latch 6300 (e.g., see FIG. 32B). Forremoval, the water reservoir 6100 can be moved horizontally out ofengagement with the spring-loaded latch 6300 along the additional,generally horizontal section 6060H2 until it reaches the drop downsection 6060D, where the water reservoir 6100 can then be pulled up andout of the reservoir dock 6050 along the drop down section 6060D and thegenerally horizontal section 6060H without pressure from thespring-loaded latch 6300.

FIGS. 80, 81, 91, and 98-101 show a guide arrangement to facilitateinsertion, alignment, and engagement of the water reservoir 6100 withthe reservoir dock 6050 according to another example of the presenttechnology.

In the illustrated example, the water reservoir 6100 includes a pair ofguiding or biasing rails 6200. As illustrated, each of the pair ofguiding rails 6200 is provided to a respective one of opposing sides ofthe base 6112 of the water reservoir 6100. When the water reservoir 6100is inserted into the reservoir dock 6050, each of the pair of guidingrails 6200 is configured to engage with a respective one of a pair ofguide slots 6060 provided to the opposite sides of reservoir dock 6050to guide coupling of the water reservoir 6100 into the reservoir dock6050.

Each of the pair of guiding rails 6200 includes an upper (with referenceto the operational orientation of the device) edge providing an upwardlyoriented surface 9300, and each of the pair of guide slots 6060 includesan upper edge providing a downwardly oriented surface 9400 (see FIGS.81, 98, and 99). When the water reservoir 6100 is inserted into thereservoir dock 6050, the guide slots 6060 are arranged to receive therails 6200 and guide the insertion of the water reservoir 6100 withinthe dock 6050. Apart from this guiding function, there is an additionalbiasing function provided by the guide slots 6060. In particular, theupwardly oriented surfaces 9300 of the rails 6200 are configured to, atleast in the last portion of their axial movement along the indicatedarrow in FIG. 81, engage and be pushed or forced downwardly byrespective downwardly oriented surfaces 9400 of the slots 6060. Thisdownward pressure forces or depresses the water reservoir 6100downwardly to, in its operational configuration, enhance abutment of itsheat conductive portion 6150 with the heater plate 6080 of the heatingassembly 6075 provided at the bottom of the reservoir dock 6050 (seeFIGS. 98 and 99).

Each of the pair of guiding rails 6200 may include one or moreengagement tabs 9315 (e.g., a single engagement tab as shown in FIGS.81, 82, and 89) extending from its upwardly oriented surface 9300configured to engage the downwardly oriented surface 9400 of arespective slot 6060, which engagement enhances displacement of thewater reservoir 6100 towards the heating assembly 6075, and therebyenhancing abutment with the heater plate 6080 of the heating assembly6075. Instead on the upwardly oriented surface 9300, the tab may belocated on the associated downward oriented surface 9400. The provisionof such a tab on one of the engagement surfaces between the rails 6200and the slots 6060 ensures a smaller friction, as instead of the entiresurface, only the area of a single tab is mechanically engaged with theopposing surface. This makes for a smoother insertion or retraction ofthe water reservoir 6100 into or out of the dock 6050, improving theuser experience.

In the illustrated example, the leading side or edge of the waterreservoir 6100 also includes one or more biasing edges or tabs 9320(e.g., a pair of biasing tabs as shown in FIG. 80) configured to engageunderneath a respective one of one or more abutment edges 9450 (e.g., apair of abutment edges as shown in FIG. 112) provided to a rear wall ofthe reservoir dock 6050 (underneath the chassis outlet 7320 and the dockoutlet 6090). Such an engagement locks the front end of the waterreservoir 6100, when fully inserted inside the dock 6050, as well asbiases downwardly the water reservoir 6100 in order to enhance abutmentof its conductive portion 6150 with the heater plate 6080 of the heatingassembly 6075 provided at the bottom of the reservoir dock 6050 (seeFIGS. 100 and 101).

That is, the downward push of the slots 6060 onto respective rails 6200(which are located at an intermediate to rear portion of the waterreservoir 6100, with the front end being the end arranged to firstlyengage with reservoir dock 6050) is complimented by a downward pushexerted by the abutment edges 9450 onto respective biasing tabs 9320 atthe front or leading side of the water reservoir 6100. The abutmentedges 9450 engage the upwardly oriented surface 9325 of respectivebiasing tabs 9320 (see FIG. 101) close to the end of the engagementprocess, when the water reservoir 6100 is almost fully inserted into thereservoir dock 6050. At this point, the pair of biasing tabs 9320 ispushed under respective ones of the abutment edges 9450, which abutmentedges 9450 are oriented generally horizontally. The abutment engagementis configured and arranged to balance the upwardly directed biasingforce provided by the heating assembly 6075 provided at the bottom ofthe reservoir dock 6050 (e.g., see FIG. 98). As described in more detailbelow, the heater plate 6080 of the heating assembly 6075 is suspendedover a resilient sealing and supporting member 9500, which is structuredand arranged to bias the heater plate 6080 upwardly against theconductive portion 6150 of the water reservoir 6100 when the waterreservoir 6100 is inserted into the reservoir dock 6050. Thus, theupward biasing force provided by the resilient sealing and supportingmember 9500 pushes from underneath the heater plate 6080, which pushesthe water reservoir 6100, which abuts the rails 6200 against respectiveslots 6060 and abuts the biasing tabs 9320 against respective abutmentedges 9450. Such arrangement ensures sufficient contact of theconductive portion 6150 of the water reservoir 6100 with the heaterplate 6080 of the water reservoir 6100.

In the illustrated example, the slots 6060 and the abutment edges 9450are arranged to be generally horizontal (e.g., generally parallel to theheater plate 6080), which arrangement allows the water reservoir 6100 tobe inserted/removed (e.g., by sliding or push/pull only) along a pathextending in a lateral direction (i.e., anterior-posterior direction)into and out of the cavity of the reservoir dock 6050. However, inalternative examples, at least a portion of the slots 6060 and/or theabutment edges 9450 may include a slope, such that at least a portion ofthe path for insertion/removal may extend in an inferior/superiordirection.

Also, as shown in FIG. 102, the lid 6114 of the water reservoir 6100includes one or more retention protrusions 6115 (e.g., a pair ofretention protrusions as shown in FIG. 80 and FIG. 85) structured andarranged to releasably engage respective dock locking edges or lockingrecesses 6051 in the reservoir dock 6050 to releasably lock and retainthe water reservoir 6100 in an operative position within the reservoirdock 6050, i.e., each protrusion 6115 engages behind the forward endforming the recess 6051. The protrusions 6115 may include a taper tofacilitate engagement of the protrusions 6115 into respective recesses6051. To release, the water reservoir 6100 may be compressed (i.e., bydepressing the lid 6114 against the base 6112) to compress thedeformable seal 6116 and allow the protrusions 6115 to lower or dropbeneath the forward end of the recess 6051. Such a locking arrangementensures that the positive pressure inside the assembled RPT device, whenin its operational configuration, does not push the water reservoirbackwards and out of operational engagement with the reservoir dock6050, thus ensuring a reliable operation of the device.

Retaining Feature

In an example, as shown in FIGS. 33A to 33F, the water reservoir 6100may comprise a latch 6400 configured to releasably engage with arecessed slot 6055 in the reservoir dock 6050 to releasably retain thewater reservoir 6100 in an operative position within the reservoir dock6050. Such a locking arrangement prevents the water reservoir fromdisengaging from the dock, which in some arrangements, the waterreservoir may be encouraged to do by the relatively high operationalpressure within the dock during the operation of the device.

In the illustrated example, the latch 6400 is provided as a separate anddistinct structure from the water reservoir 6100 and then secured orotherwise provided to the water reservoir 6100 in an operative position,e.g., the latch 6400 comprises a pre-formed structure that is secured tothe reservoir lid 6114, or to other portions of the water reservoir6100. In an example, the latch 6400 comprises a plastic or thermoplasticpolymer material.

As shown in FIGS. 33E and 33F, the latch 6400 includes a locking lever6402, a lid connector 6404, and support members 6406 to resilientlysupport the locking lever 6402 to the lid connector 6404.

As shown in FIG. 33G, the reservoir lid 6114 includes a recess 6260 toreceive the latch 6400. Each side of the recess 6260 includes a rail6262, and a bottom of the recess includes a locking tab 6264. Each rail6262 forms a slot configured to receive a respective side of the lidconnector 6404. The lid connector 6404 is guided by the rails 6262 intothe recess 6260 until the slotted end 6405 of the lid connector 6404engages behind the locking tab 6264 to secure the latch 6400 to thereservoir lid 6114 in an operative position, e.g., see FIGS. 33C and33D.

The locking lever 6402 includes a retaining protrusion 6403 at one endof the locking lever 6402 and a finger/thumb grip 6407 at the other endof the locking lever 6402. The locking lever 6402 is supported by theresilient support members 6406 such that the retaining protrusion 6403is resiliently biased to a locked position.

When the water reservoir 6100 reaches an operative position in thereservoir dock 6050, the retaining protrusion 6403 of the latch 6400 isconfigured and arranged to engage over and behind the forward ledgeforming the recessed slot 6055 in the reservoir dock 6050, e.g., seeFIG. 33B. The retaining protrusion 6403 includes a taper to facilitateengagement of the retaining protrusion 6403 into the recessed slot 6055.This connection releasably secures the water reservoir 6100 to thereservoir dock 6050. The finger/thumb grip 6407 can be manuallydepressed to pivot the locking lever 6402 and hence the retainingprotrusion 6403 against the external bias of members 6406 and into anunlocked position, i.e., retaining protrusion 6403 pivoted out of therecessed slot 6055 to allow the water reservoir 6100 to be removed fromthe reservoir dock 6050.

Air Delivery Tube to Reservoir Dock Connection

In an example, e.g., as shown in FIGS. 20A, and 23A to 24B, the airdelivery tube 4170 includes a tube portion 4500, a dock connector/cuff4600 (outlet connector) to connect the air delivery tube 4170 to thereservoir dock 6050 and/or the water reservoir 6100, and a patientinterface connector/cuff 4700 (inlet connector) to connect the airdelivery tube 4170 to the patient interface 3000.

In an example, the dock connector 4600 is structured and arranged toform a mechanical and electrical connection with the reservoir dock 6050and to form a pneumatic connection with the water reservoir 6100 and/orwith the reservoir dock 6050. These connections locate and secure theair delivery tube 4170 to the reservoir dock 6050 or the water reservoir6100, provide electrical power, information and control signals to theheating element and transducers associated with the air delivery tube4170, and allow humidified, pressurized gas to flow from the waterreservoir 6100 to the patient interface 3000. During the engagement ofthe air delivery tube 4170 with the water reservoir 6100 and thereservoir dock 6050, the connections may be formed simultaneously or inseries, e.g., one of the mechanical, pneumatic or electrical connectionsmay be completed before others.

The dock connector 4600 of the air delivery tube 4170 includes aretention feature that provides a fixed, non-rotatable connection withthe dock outlet 6090 of the reservoir dock 6050.

In one example, as shown in FIGS. 23A and 23B, the retention feature ofthe dock connector 4600 includes a pair of resilient, quick releasepinch arms 4610, i.e., cantilevered spring arms or pinch buttons. Eachof the spring or pinch arms 4610 may include a barbed end or tabstructured to provide a snap-fit connection with the dock outlet 6090.In an example, the dock outlet 6090 may include locking members, e.g.,slots, structured and arranged to receive a respective barbed end of thepinch arms 4610.

The free end of the dock connector 4600 includes an outwardly extendingflange or lip 4620 surrounding the tube opening. The flange or lip 4620provides a generally planar contact surface 4625. When the dockconnector 4600 is connected to the dock outlet 6090, the free end of thedock connector 4600 and contact surface 4625 thereof protrudes into thecavity of the reservoir dock 6050 to allow engagement with the outlettube 6130 of the water reservoir 6100, e.g., as shown in FIG. 22C.

In the example of FIGS. 23A and 23B, the dock connector 4600 of the airdelivery tube 4170 includes a longitudinal axis A1 (e.g., aligned withthe axis of the tube, which may also be the axis ofengagement/disengagement with the dock outlet 6090), and a contactsurface 4625 arranged along an axis A2 that extends at an angle to thelongitudinal axis A1, e.g., 45°. Such arrangement orients the contactsurface 4625 for engagement with the water reservoir 6100 as describedbelow.

FIGS. 20A and 24A to 24B show an air delivery tube 4170 including a dockconnector 4600 according to alternative example of the presenttechnology. As illustrated, each side of the dock connector 4600includes a retaining protrusion 4615 structured to provide a snap-fitconnection with the dock outlet 6090.

In an example, as best shown in FIGS. 20A to 20C, 20K, and 20L, the dockoutlet 6090 may include a locking arrangement 6600 to receive andreleasably retain the air delivery tube 4170 in an operative positionwithin the dock outlet 6090. As illustrated, the locking arrangement6600 includes a button portion 6605 and locking arms 6610 extending fromthe button portion 6605. Each locking arm 6610 includes a locking tab6615 arranged to engage a respective retaining protrusion 4615 of thedock connector 4600. The locking arrangement 6600 is supported adjacentthe dock outlet 6090 such that the locking arms 6610 and locking tabs6615 thereof are resiliently biased to a locked position.

When the dock connector 4600 of the air delivery tube 4170 is insertedinto the respective dock opening 6091 and reaches an operative positionin the dock outlet 6090 of the reservoir dock 6050, the retainingprotrusions 4615 of the dock connector 4600 are configured and arrangedto engage over and behind respective locking tabs 6615 of the lockingarrangement 6600, e.g., see FIG. 20K. In some arrangements, the dockconnector 4600 of the air delivery tube 4170 may have to be insertedinto the respective dock opening 6091 and rotated, in order to effectthis locking engagement with the locking arrangement 6600. Eachretaining protrusion 4615 and/or each locking tab 6615 may include ataper to facilitate engagement into a locked position. This connectionreleasably secures the air delivery conduit 4170 to the reservoir dock6050, e.g., see FIGS. 20D to 20H. As shown in FIG. 20L, the buttonportion 6605 can be manually depressed to resiliently flex the lockingarms 6610 and locking tabs 6615 thereof against biasing to an unlockedposition, i.e., locking tabs 6615 moved laterally outwardly out ofengagement with the retaining protrusions 4615 of the dock connector4600 to allow the air delivery conduit 4170 to be removed from the dockoutlet 6090 of the reservoir dock 6050.

Once the connection is established, the retaining features provided bythe dock connector 4600/locking arrangement 6600, as well as thenon-circular engagement profile provided by the dock opening 6091 of thedock outlet 6090 (see FIG. 20C) and the dock connector 4600, provides afixed, non-rotatable connection of the air delivery conduit 4170 to thedock outlet 6090.

The free end of the dock connector 4600 includes an outwardly extendingflange or lip 4620 surrounding the tube opening, e.g., see FIGS. 20A,20G, 20I, and 20J. The flange or lip 4620 provides a contact surface4625. When the dock connector 4600 is connected to the dock outlet 6090,the free end of the dock connector 4600 and contact surface 4625 thereofprotrudes into the cavity of the reservoir dock 6050 to allow engagementwith the water reservoir 6100, e.g., see FIGS. 20F to 20H.

Similar to the above example, the contact surface 4625 of the dockconnector 4600 shown in FIGS. 20A and 24A to 24B is arranged along anaxis that extends at an angle to the longitudinal axis of the tube,e.g., 45°.

Water Reservoir/Air Delivery Tube—Direct Engagement Under 45°

A direct, pneumatic connection between the water reservoir 6100 and theair delivery conduit 4170 was already discussed above. In theillustrated example of FIGS. 18A and 18B, the water reservoir 6100includes an axis A1 (e.g., aligned with the direction ofinsertion/removal), and the outer end of the outlet tube 6130 (oroutlet) and the outlet seal thereof is arranged along an axis A2 thatextends at an angle to the axis A1, e.g., 45°. As described above inrelation to FIGS. 23A and 23B, the dock connector 4600 of the airdelivery tube 4170 includes an axis A1 (e.g., aligned with direction ofinsertion/removal of the air delivery tube 4170), and a contact surface4625 of the dock connector 4600 is arranged along an axis A2 thatextends at an angle to the axis A1, e.g., 45°.

When the air delivery tube 4170 is engaged with the water reservoir 6100and/or the dock outlet 6090 of the reservoir dock 6050, the outlet tube6130 (or outlet) and outlet seal 6132 of the water reservoir 6100 isstructured to sealingly engage or interface against the contact surface4625 along the free end of the dock connector 4600 of the air deliverytube 4170, e.g., see FIGS. 21 and 22A to 22C. Such engagement provides aface seal between the water reservoir 6100 and the dock connector 4600to seal the outlet flow path that allows humidified air to flow out ofthe water reservoir 6100 and into the air delivery tube 4170 fordelivery to the patient interface 3000.

The engagement profile of the outlet tube 6130 (and outlet seal 6132)and contact surface 4625, e.g., at 45°, allows the water reservoir 6100to be removed from the reservoir dock 6050 while the air delivery tube4170 remains attached to the dock outlet 6090. Similarly, this 45° angleallows the air delivery tube 4170 to be disengaged from the dock,without the need for the water reservoir 6100 to be removed from thereservoir dock 6050 outlet 6090. Thus, the insertion and removal of thewater reservoir 6100 may be independent of the connection of the airdelivery tube 4170 to the dock outlet 6090, i.e., water reservoir 6100and air delivery tube 4170 may be engaged/disengaged with the reservoirdock 6050 independently.

It should be appreciated that the outlet tube 6130 (and outlet seal6132) and the contact surface 4625 may be arranged at other suitableangles for direct contact with one another.

In an alternative example, the air delivery tube 4170 may not directlycontact the reservoir dock 6050. Instead, a tube adaptor may be providedto interconnect an air delivery tube 4170 to the reservoir dock 6050.The tube adaptor may include a dock connector end for connection to thereservoir dock 6050 and a tapered/ISO (standardized) end for connectionto an air delivery tube 4170. The tube adaptor may include a lockoutfeature to prevent removal of the air delivery tube 4170 from the tubeadaptor when the tube adaptor is connected to the dock outlet 6090 ofthe reservoir dock 6050.

Data Collection

In an example, the air delivery tube 4170 may include a plurality ofwires helically wound around the axis of the air delivery tube 4170(e.g., along the tube portion 4500 of the air delivery conduit 4170),e.g., configured to heat air in the air delivery tube and/or transmitsignal from one or more transducers (e.g., temperature sensor, flowsensor) to a controller of the RPT device.

In an example, the air delivery tube 4170 may comprise four wires, e.g.,two wires for powering one or more heating elements and two wires forconnecting a temperature sensor/transducer. However, it should beappreciated that other numbers of wires may be used, e.g., two wires,three wires, or five or more wires.

In an example (e.g., see FIGS. 23B and 24A), the dock connector 4600 ofthe air delivery tube 4170 includes a contact assembly 4650 includingcontacts 4655 that, in use, are engaged with respective contactsprovided to the reservoir dock 6050 to form electrical connections withthe reservoir dock at the dock outlet to provide electrical power and/orcontrol signal transmission. In an example, the contacts 4655 of thedock connector 4600 may be joined to respective wires running along theair delivery tube 4170. In an alternative example, the at least some ofthe contacts 4655 are not related to the wires running along the airdelivery tube 4170, but are characterised by their own independentand/or unique electrical characteristics (e.g., resistance, conductance,etc.). Such independent and/or unique electrical characteristics may beused for identifying one or more elements of the tube/patient interfacesystem, or of characteristics of these elements.

In an example, the dock outlet 6090 of the reservoir dock 6050 includesa contact assembly 6800 in communication with electrical power andelectrical signalling within the reservoir dock, e.g., the PCBA 7600. Inan example, the contact assembly 6800 includes contacts 6805corresponding to the number of contacts 4655 provided to the dockconnector 4600 of the air delivery tube 4170, e.g. four contacts asshown in FIGS. 20B, 20C, 20H to 20J. In an example, as shown in FIGS.20H to 20J, each of the contacts 6805 comprises a spring loaded pin(e.g., pogo-pin). In use, the spring loaded pins 6805 will resilientlydeflect during engagement with the dock connector 4600 to maintaincontact with respective contacts 4655 of the dock connector 4600. In theillustrated example (e.g., see FIG. 20J), the contact assembly 6800 alsoincludes contacts 6810 (e.g., spring loaded pins) arranged to engage thePCBA 7600. The contacts 6805, 6810 are supported by a support member6815 configured to orient the contacts 6805 substantially perpendicularto the contacts 6810.

Because each contact 4655, or combination of contacts, in the contactassembly 4650 of the air delivery tube 4170 may have unique electricalcharacteristic, in an example, the contact assembly 4650 of the airdelivery tube 4170 may be used as an identifier of various parameters ofthe air delivery tube 4170 and/or the patient interface. For example,the contact assembly 4650 may be configured to provide identification ofthe type of air delivery tube 4170 (e.g., non-heated tube, heated tube,tube with heat and moisture exchanger (HME), tube unknown), size of airdelivery tube (e.g., 15 mm, 19 mm), presence and type of HME, type ofpatient interface connected to tube, etc. The data from identificationmay be communicated and used by a controller, e.g., to optimizeoperation of the RPT device, humidifier, to facilitate data collection,etc. For example, the controller may be configured to recognize a uniqueidentifying feature provided by the contact assembly 4650 so that thecontroller can recognize the specific characteristics of the airdelivery tube 4170 coupled to the reservoir dock 6050, and therefore thecontroller can automatically configure the RPT device and/or humidifierto optimize operation.

In an example, the dock connector 4600 may include a tapered supportprotrusion 4630 (e.g., see FIGS. 20A, 20M, and 20N). When the dockconnector 4600 of the air delivery tube 4170 is connected to the dockoutlet 6090 of the reservoir dock 6050, the tapered support protrusion4630 is adapted to be arranged adjacent to or in contact with one ormore tapered support protrusions 6850 provided to the dock outlet 6090as best shown in FIGS. 20M and 20N. The tapered support protrusions4630, 6850 provide an interface between the dock connector 4600 and thedock outlet 6090 to maintain the dock connector 4600 in generallyperpendicular relation to the front face of the dock outlet 6090, e.g.,interface prevents the dock connector 4600 from sagging or tiltingdownwardly away from the dock outlet 6090. For example, the interfacebetween the dock connector 4600 and the dock outlet 6090 may counteractforce applied by the contact assembly 6800 to the dock connector 4600which tends to force the dock connector 4600 downwardly, e.g., forceapplied by spring loaded pins of the contact assembly 6800 are offsetfrom the axis of the dock connector 4600 which may force the dockconnector 4600 at a downward angle away from the dock outlet 6090.

Bayonet-Style Connection and Intermediate Component

FIGS. 43 to 78 illustrate an alternative example for connecting the airdelivery tube 4170 to the reservoir dock 6050 and the water reservoir6100. In this example, an intermediate component 6700 is removablycoupled to the reservoir dock 6050. The intermediate component 6700 isconfigured to pneumatically connect the water reservoir 6100 to the airdelivery tube 4170 so that the pressurized flow of air that has beenhumidified in the water reservoir 6100 can be delivered from the waterreservoir 6100, via the intermediate component 6700, to the air deliverytube 4170. Also, in this example, the dock connector 4600 of the airdelivery tube 4170 is structured and arranged to form a bayonet-styleconnection with the reservoir dock 6050, which mechanically and/orelectrically connects the air delivery tube 4170 with the reservoir dock6050. That is, the bayonet-style connection locates and secures the airdelivery tube 4170 to the reservoir dock 6050 and/or provides electricalpower, information and control signals to the heating element andtransducers associated with the air delivery tube 4170.

Intermediate Component

As shown in FIGS. 43, 46, 49, 57, and 58, the intermediate component6700 is provided to the dock outlet 6090 of the reservoir dock 6050 topneumatically connect the water reservoir 6100 to the air delivery tube4170. In the illustrated example, the intermediate component 6700 isremovably coupled to the reservoir dock 6050 so that the intermediatecomponent 6700 can be disassembled for cleaning, sterilization and/orreplacement, e.g., for multi-patient multi-use (MPMU) applications.

As shown in FIGS. 53-56, the intermediate component 6700 comprises atubular portion 6705 including an inlet end 6710 adapted to interfacewith the water reservoir 6100 and an outlet end 6720 adapted tointerface with the air delivery tube 4170. The intermediate component6700 also comprises retention and alignment features structured andarranged to align the intermediate component 6700 with the reservoirdock 6050 and provide a removable, non-rotatable connection with thereservoir dock 6050. In addition, the intermediate component 6700comprises a port 6730, e.g., a pressure port for inserting a sensor formeasuring air pressure at the dock outlet 6090. The port 6730 includes aport seal 6735 to provide a sealing interface between a sensor, e.g.,pressure sensor, and the intermediate component 6700.

In the illustrated example, e.g., see FIG. 56, the tubular portion 6705(including the inlet end 6710 and the outlet end 6720) along with theretention and alignment features comprise a first part or base moldconstructed of a relatively rigid material (e.g., thermoplastic polymer(e.g., PC, ABS)) and the port seal 6735 comprises a second part orovermold constructed of a relatively soft material (e.g., thermoplasticelastomer (TPE) or silicone) that is provided (e.g., by overmolding) tothe first part. Thus, the intermediate component 6700 provides asubstantially rigid construction, e.g., for durability for MPMUapplications.

In the illustrated example, the inlet end 6710 is arranged at an angleto the outlet end 6720, e.g., the axis of the inlet end is arranged atabout 90° with respect to the axis of the outlet end. However, it shouldbe appreciated that other suitable angles are possible, e.g., the axisof the inlet end is arranged at about 45° with respect to the axis ofthe outlet end.

The free end of the inlet end 6710 includes a flange or lip 6712surrounding the tube opening. The flange or lip 6712 provides a contactsurface 6715. When the water reservoir 6100 is coupled to the reservoirdock 6050, the outlet seal 6132 of the outlet tube 6130 (or outlet) ofthe water reservoir 6100 is structured to engage and provide a face sealwith the contact surface 6715 of the inlet end 6710. In an alternativeembodiment, the seal between the outlet tube 6130 (or outlet) of thewater reservoir 6100 and the contact surface 6715 of the inlet end 6710may be an integral part of the inlet end 6710, or may be a sealingportion independent from either the outlet tube 6130 or the inlet end6710. In the illustrated example, the contact surface 6715 comprises ataper into the tube opening, e.g., to enhance sealing and prevent leak.

The outlet end 6720 may comprise an ISO taper, e.g., 22 mm outerdiameter ISO taper, for coupling to the air delivery conduit 4170.

In regards to retention and alignment features, the intermediatecomponent 6700 includes a pair of resilient pinch arms 6740, i.e.,cantilevered spring arms. Each of the spring or pinch arms 6740 mayinclude a barbed end or tab 6745 structured to provide a snap-fitconnection with respective locking members, e.g., protrusions 6750,provided within the cavity of the reservoir dock 6050 as shown in FIG.46. The intermediate component 6700 also includes a guide rail 6760structured and arranged to assist in correct alignment and insertion ofthe intermediate component 6700 into the reservoir dock 6050 byengagement with a corresponding guide slot 6755 extending into thecavity of the reservoir dock 6050 as shown in FIGS. 46, 50 and 52.Further, the intermediate component 6700 includes a flange 6770 arrangedbetween the inlet end 6710 and the outlet end 6720 to assist in locatingor positioning the intermediate component 6700 in the reservoir dock6050 by abutting a flange or wall provided to the reservoir dock 6050,e.g., flange acts as a stop during insertion as shown in FIG. 72. Theflange 6770 of intermediate component 6700 may include one or morecut-outs or recesses 6772, e.g., to accommodate fasteners or projectionsalong the flange or wall provided to the reservoir dock 6050 as shown inFIGS. 57 and 58.

When the intermediate component 6700 is inserted into the dock opening6091 of the reservoir dock 6050, the intermediate component 6700 isoriented to engage its guide rail 6760 with the guide slot 6755 whichcorrect aligns and guides the intermediate component 6700 into anoperative position. Also, the dock opening 6091 and/or an opening 6919provided by the locking and contact assembly 6900 at the dock opening6091 includes a non-circular profile to facilitate correct orientationof the intermediate component 6700 during insertion as shown in FIG. 63.When the intermediate component 6700 reaches an operative position, thebarbed ends or tabs 6745 of the spring or pinch arms 6740 are configuredand arranged to engage over and/or behind respective protrusions 6750,e.g., see FIG. 46. Each barbed end 6745 and/or each protrusion 6750 mayinclude a taper to facilitate engagement into the operative position. Inan example, the engagement of the spring or pinch arms 6740 with theprotrusion 6750 may provide sensory feedback, e.g., audible click, toindicate correction connection. This snap-fit connection releasablysecures the intermediate component 6700 to the reservoir dock 6050. Todisengage the intermediate component 6700, the spring or pinch arms 6740can be manually depressed towards one another (e.g., with or without atool) to resiliently flex the spring or pinch arms 6740 and barbed ends6745 thereof against biasing to an unlocked position, i.e., barbed ends6745 moved out of engagement with the protrusion 6750 to allow theintermediate component 6700 to be removed from the reservoir dock 6050.

Once the connection is established, the cooperating retention andalignment features provided by the intermediate component 6700/reservoirdock 6050 provides a removable, non-rotatable connection of theintermediate component 6700 to the dock outlet 6090 of the reservoirdock 6050. Also, once connected, the spring or pinch arms 6740 of theintermediate component 6700 are lockingly engaged within the cavity ofthe reservoir dock 6050, e.g., to prevent removal of the intermediatecomponent 6700 when the water reservoir 6100 is received in thereservoir dock 6050.

When the intermediate component 6700 is connected to the dock outlet6090 of the reservoir dock 6050, the inlet end 6710 and contact surface6715 thereof protrudes into the cavity of the reservoir dock 6050 toallow engagement with the outlet seal 6132 of the outlet tube 6130 (oroutlet) of the water reservoir 6100, e.g., see FIG. 46. Likewise, theoutlet end 6720 of the intermediate component 6700 extends within,and/or protrudes out, of the cavity of the reservoir dock 6050 to allowengagement with the air delivery tube 4170, e.g., see FIG. 43. Further,the port 6730 of the intermediate component 6700 is oriented, e.g.,upwardly as shown in FIG. 57, to interface with the sensor associatedwith the PCBA.

Bayonet-Style Locking and Contact Assembly

As shown in FIGS. 43-52, a locking and contact assembly 6900 is providedto the dock outlet 6090 of the reservoir dock 6050 to mechanically andelectrically connect the reservoir dock 6050 to the air delivery tube4170. In the illustrated example, the locking and contact assembly 6900comprises a bayonet-style connection structured and arranged to locateand secure the air delivery tube 4170 to the reservoir dock 6050 andform mechanical, pneumatic and electrical (both power and controlsignals) connections.

As shown in FIGS. 59-62, the locking and contact assembly 6900 includesa base 6910, an (electrical) contact assembly 6950 provided to the base,and a cover 6970 provided to the base 6910 to enclose at least a portionof the contact assembly 6950.

The base 6910 includes a rear wall 6912 that is secured, e.g., via oneor more fasteners, to one or more walls surrounding the dock opening6091 so as to secure the base 6910 at the dock outlet 6090 of thereservoir dock 6050. As shown in FIG. 63, the rear wall 6912 includes anopening 6915, e.g., non-circular, that aligns with the dock opening 6091to allow insertion and connection of the intermediate component 6700 asmentioned above, e.g., a non-circular opening 6915 adapted to receivenon-circular profile of the intermediate component 6700. Further, asmentioned above, the rear wall 6912 provides a stop for the intermediatecomponent 6700 during assembly, e.g., at least a portion of the flange6770 of the intermediate component 6700 may abut the rear wall 6912 asshown in FIG. 72.

The base 6910 includes an annular side wall 6920 that projects outwardlyfrom the rear wall 6912. When the intermediate component 6700 isconnected to the reservoir dock 6050, the outlet end 6720 of theintermediate component 6700 and the annular side wall 6920 cooperate toform a channel 6780 for receiving the air delivery tube 4170. Aretaining wall 6930 projects radially outwardly from the annular sidewall 6920 along a portion of the perimeter of the annular side wall,e.g., along a portion of the superior side of the annular side wall.With reference to FIG. 57, a gap is provided in the annular side wall6920 along a portion of the perimeter of the annular side wall whichforms a recess 6940 that leads into the channel 6780. The recess 6940 isadjacent to, and disposed counter-clockwise from, the retaining wall6930. As described below, the recess 6940 and retaining wall 6930 areconfigured and arranged so that a portion of the dock connector 4600 ofthe air delivery tube 4170 may be inserted into the recess 6940 and thenrotated clockwise, to move behind retaining wall 6930, to effect alocking engagement between the air delivery tube and the dock.

Additional retention and alignment features, e.g., recesses and/orgrooves, are provided to the annular side wall 6920 along its perimeterthat are structured and arranged to interact with corresponding featureson the dock connector 4600 of the air delivery tube 4170 duringengagement as discussed below.

As shown in FIGS. 60-62, the electrical contact assembly 6950 issupported by the base 6910 adjacent the retaining wall 6930. The contactassembly 6950 is in communication with electrical power and electricalsignalling within the reservoir dock 6050, e.g., the PCBA 7600. Asillustrated, the contact assembly 6950 includes a support member 6952and a plurality of contacts 6955, e.g., four contacts, supported by thesupport member 6952. Each of the contacts 6955 comprises a spring arm6956 (as best seen in FIG. 61) that is biased away from the supportmember 6952. In use, when the tube engages with the dock, the springarms 6956 will resiliently deflect during engagement with the dockconnector 4600 to maintain contact with respective contacts of the dockconnector 4600. The contact assembly 6950 also includes an electricalconnector 6958, e.g., flexible circuit board (FCB), flexible printedcircuits (FPC) and/or flexible flat cables (FFC), to electricallyconnect the contacts 6955 to the PCBA 7600 (see FIG. 62).

The superior side of the base 6910 includes a contact support structure6960 (FIG. 62) structured and arranged to support and retain the supportmember 6952 of the contact assembly 6950 (FIG. 61), which supports thecontacts 6955 of the contact assembly 6950 radially outwardly of theannular side wall 6920 and axially inwardly of the retaining wall 6930.The cover 6970 is secured to the superior side of the base 6910 toenclose at least the support member 6952 and contacts 6955 (see FIG.60). The electrical connector 6958 protrudes from the base 6910, e.g.,through one or more slots in the base, to connect to the PCBA 7600 (FIG.62).

Dock Connector

As shown in FIGS. 43-45, the dock connector 4600 of the air deliverytube 4170 is structured to form a pneumatic connection with theintermediate component 6700 and form a mechanical and electricalconnection with the locking and contact assembly 6900 provided to thereservoir dock 6050.

In the illustrated example, the dock connector 4600 includes a tubularbase portion 4640 and a locking and contact assembly 4660 provided tothe base portion 4640.

As shown in FIGS. 64-68, the tubular base portion 4640 includes a radiallip seal 4645 that protrudes into the opening of the base portion 4640.The radial lip seal 4654, in its relaxed, undeformed shape, provides aninternal diameter that is smaller than the external diameter of theoutlet end 6720 of the intermediate component 6700 with which the dockconnector pneumatically engages. For example, the internal diameterprovided by the radial lip seal 4645 may be less than about 22 mm (e.g.,about 19-21 mm or less) for use with an outlet end 6720 comprising a 22mm outer diameter ISO taper. In use, the radial lip seal 4645 isstructured to resiliently deform upon engagement with the outlet end6720 of the intermediate component 6700 so as to provide a pneumaticconnection with the intermediate component 6700, e.g., radial lip seal4645 forms a gas tight seal against the exterior surface of the outletend 6720 of the intermediate component 6700. As illustrated, the radiallip seal 4645 extends at an angle towards the interior of the baseportion 4640 to provide a lead in for aligning and engaging the dockconnector 4600 with the intermediate component 6700. Also, a stopsurface 4647 (see FIG. 66) within the base portion 4640 provides a stopto prevent the intermediate component 6700 from being inserting furtherinto the dock connector 4600.

The base portion 4640 includes a tapered protrusion 4642 that protrudesoutwardly from the base portion 4640 (see FIG. 64) adjacent the lockingand contact assembly 4660. The tapered protrusion 4642 provides a thumband/or finger grip to facilitate manual manipulation and connection ofthe dock connector 4600 with the intermediate component 6700 and thelocking and contact assembly 6900 provided to the reservoir dock 6050.

Further, the base portion 4640 includes resilient retaining bumps 4644along opposing sides thereof. As described below, the retaining bumps4644 are structured and arranged to interact with retention andalignment features, e.g., recesses and/or grooves, provided to the base6910 of the locking and contact assembly 6900 on the reservoir dock 6050during engagement.

In the illustrated example, as shown in FIG. 68, the base portion 4640may comprise a base 4640 bs (e.g., comprising one or more parts)constructed of a relatively rigid material (e.g., thermoplastic polymer(e.g., polypropylene (PP), polycarbonate (PC), and Acrylonitrilebutadiene styrene (ABS)) and an overmold 4640 ov constructed of arelatively soft material (e.g., thermoplastic elastomer (TPE) orsilicone) that is provided (e.g., by overmolding) to the base 4640 bs.As illustrated, the relatively rigid base 4640 bs may form thestructural shape for the tubular base portion 4640 including the taperedprotrusion 4642 and resilient retaining bumps 4644 while the relativelysoft overmold 4640 ov forms the exterior for the tubular base portion4640 along with the radial lip seal 4645.

As shown in FIG. 64, the locking and contact assembly 4660 includes aretaining portion 4665, a support arm 4662 to support the retainingportion 4665 in spaced relation from the base portion 4640, and acontact assembly 4666 provided to the retaining portion 4665. Asdescribed below, the retaining portion 4665 is structured and arrangedto be rotated behind the retaining wall 6930 provided to the locking andcontact assembly 6900 on the reservoir dock 6050 to axially lock thedock connector 4600 in a locked position. The contact assembly 4666includes contacts 4667 that, in use, are arranged to engage withrespective contacts 6955 provided to the locking and contact assembly6900 on the reservoir dock 6050 to form electrical and control signalconnections with the reservoir dock 6050. The contacts 4667 are arrangedalong the retaining portion 4665 to form the electrical and signalconnections as the dock connector 4600 is rotated into the lockedposition. An electrical connector 4668, e.g., flexible circuit board(FCB), flexible printed circuits (FPC) and/or flexible flat cables(FFC), electrically connects the contacts 4667 to respective wiresrunning along the air delivery tube 4170 and/or circuit elements. Thefact that, as shown in FIG. 64, the contact tracks extend in acircumferential direction allows them to initiate and maintain theelectrical connection, whilst the dock connector 4600 is being rotatedwithin the locking and contact assembly 6900.

Engagement of Dock Connector with Reservoir Dock

FIGS. 43-45 and 69-78 illustrate engagement of the dock connector 4600of the air delivery tube 4170 with the reservoir dock 6050. As shown inFIG. 43, the dock connector 4600 is oriented to align its locking andcontact assembly 4660 with the recess 6940 provided by the locking andcontact assembly 6900 on the reservoir dock 6050. The dock connector4600 is then pushed towards the reservoir dock 6050 so that the outletend 6720 of the intermediate component 6700 extends into the opening ofthe base portion 4640 and the radial lip seal 4645 engages andresiliently deforms against the exterior surface of the outlet end 6720.The radial lip seal 4645 of the dock connector 4600 engages and slidesalong the exterior surface of the outlet end 6720 of the intermediatecomponent 6700 as the dock connector 4600 is pushed further towards thereservoir dock 6050 into an unlocked, engaged position.

As shown in FIGS. 44 and 69-72, when the dock connector 4600 reaches theunlocked, engaged position, the base portion 4640 of the dock connector4600 is received within the channel 6780 formed by the base 6910 and theintermediate component 6700, and the locking and contact assembly 4660of the dock connector 4600 is received within the recess 6940. In anexample, the forward end of the base portion 4640 may engage the flange6770 of the intermediate component 6700 and/or the stop surface 4647within the base portion 4640 may engage the free end of the outlet end6720 to prevent the dock connector 4600 from inserting further into thelocking and contact assembly 6900.

Further, when the dock connector 4600 reaches the unlocked, engagedposition, the retaining bumps 4644 of the dock connector 4600 areoriented to engage within respective recesses provided to the annularside wall 6920 of the base 6910, e.g., one of the bumps 4644 engageswithin a closed, elongated recess 6922 and the other of the bumps 4644engages within an open-ended recess 6924. The friction forces keepingthe bumps inside the engagement grooves may be calibrated to besufficient to maintain the tube inside in this engaged, but unlockedconfiguration when the device is under operational pressure. Thus, inthis configuration, there may be a full operational pneumatic engagementbetween the tube and the dock. However, mechanically the engagement isuncompleted. Also, the tube and the dock are not in electricalcommunication in this configuration.

As shown in FIGS. 45 and 73-78, the dock connector 4600 is rotated in aclockwise direction from the unlocked, engaged position into a lockedposition which locks the dock connector 4600 to the reservoir dock 6050and forms electrical and control signal connections with the reservoirdock 6050. When the dock connector 4600 reaches the locked position, theretaining portion 4665 is rotated over the annular side wall 6920 andbehind the retaining wall 6930 provided to the locking and contactassembly 6900 which prevents the dock connector 4600 from being pulledaxially outwardly from the reservoir dock 6050. Also, the contacts 4667along the retaining portion 4665 are rotated into engagement withrespective spring arms 6956 of the contact 6955 provided to the lockingand contact assembly 6900 which forms the electrical and control signalconnections with the reservoir dock 6050.

Further, when the dock connector 4600 reaches the locked position, theone bump 4644 rotates within the closed, elongated recess 6922 and theother bump 4644 rotates out of the open-ended recess 6924 and into anadjacent open-ended recess 6926. Such engagement of the bumps 4644within respective recesses provides retention, provides alignmentfeatures, and provides tactile feedback during engagement. In addition,the locking and contact assembly 6900 may include a stop wall 6935 (seeFIG. 70) arranged to engage the locking and contact assembly 4660 of thedock connector 4600 when the dock connector 4600 reaches the lockedposition to prevent further rotation of the dock connector 4600, e.g.,see FIG. 74.

In this example, connection of the dock connector 4600 with thereservoir dock 6050 is configured so that the pneumatic connection iscompleted prior to the electrical and mechanical connections. In anotherexample, the electrical, pneumatic and mechanical connections may beformed simultaneously, either when the dock connector is rotated intothe locked position, or by removing the rotational functionality fromthe connection.

To allow removal of the air delivery conduit 4170 from the reservoirdock 6050, the dock connector 4600 can be rotated in a counter-clockwisedirection from the locked position into the un-locked, engaged position.This rotates the locking and contact assembly 4660 of the dock connector4600 into the recess 6940 provided by the locking and contact assembly6900. Such rotation disengages the dock connector 4600 electrically fromthe reservoir dock 6050 and allows the dock connector 4600 to be pulledoutwardly away from the reservoir dock 6050 for disengagement.

Straight Plug-In Connection and Intermediate Component

FIGS. 110 to 133 illustrate an alternative example of engagement betweenthe dock connector 4600 of air delivery tube 4170 and the humidificationtub 6100. The arrangement involves a different configuration of theintermediate component 9700 for connecting the air delivery tube 4170 tothe reservoir dock 6050 and the water reservoir 6100, as best seen inFIGS. 116-120. In this example, the intermediate component 9700 isremovably coupled to the reservoir dock 6050 and is configured topneumatically connect the water reservoir 6100 to the air delivery tube4170 so that the pressurized flow of air that has been humidified in thewater reservoir 6100 can be delivered from the water reservoir 6100, viathe intermediate component 9700, to the air delivery tube 4170. Also, inthis example, the intermediate component 9700 is configured to alsoreleasably mechanically/lockingly connect to the air delivery tube 4170,which locates and releasably retains the air delivery tube 4170 to thereservoir dock 6050. Further, the arrangement is such that, whilst theair delivery tube 4170 is mechanically locked and pneumatically engagedwith the intermediate component 9700, it can also form an electricalconnection with the reservoir dock 6050. This electrical connectionprovides electrical power, information and control signals to theheating element and transducers associated with the air delivery tube4170. Each two of the following connections; locking mechanicalengagement, the pneumatic engagement and the electrical engagement canbe effected sequentially or substantially simultaneously. If theengagements are effected sequentially, the specific order in which theyare effected can vary. In one example, during the connection of the airdelivery tube to the intermediate component, the pneumatic engagement mebe effected first, followed by the substantially simultaneous engagementof the mechanical/locking and the electrical engagements. In anotherexample, the locking mechanical engagement, the pneumatic and theelectrical engagement can be effected substantially simultaneously uponconnecting the air delivery tube to the intermediate component.

In the example described above in relation to FIGS. 43-78, the dockconnector 4600 pneumatically seals with the intermediate component 6700and mechanically connects (locks) with the reservoir dock 6050. Incontrast in this later example shown in FIGS. 110 to 133, the dockconnector 4600 of the air delivery tube 4170 forms both a pneumatic sealand a mechanical (locking) connection with the intermediate component9700 in the example of FIGS. 110-133. By combining the pneumatic andmechanical connections into one component, the dimensional tolerancescan improve, which may make the dock connector 4600 more reliable andeasier to manufacture, and may also allow reduction in the size of thedock connector 4600.

Intermediate Component

As shown in FIGS. 110, 112, 113, and 115A, the intermediate component9700 is provided to, and mechanically engaged with, the dock outlet 6090of the reservoir dock 6050 to pneumatically connect the water reservoir6100 to the air delivery tube 4170 and mechanically connect the airdelivery tube 4170 to the reservoir dock 6050. In the illustratedexample, the intermediate component 9700 is removably coupled to thereservoir dock 6050 so that the intermediate component 9700 can bedisassembled for cleaning, sterilization and/or replacement, e.g., formulti-patient multi-use (MPMU) applications.

As shown in FIGS. 113 and 116-120, the intermediate component 9700comprises a tubular portion 9705 including an inlet end 9710 and anoutlet end 9720. The inlet end 9710, best shown in FIG. 120, is providedwith an inlet seal 9715 adapted to interface with the water reservoir6100, and the outlet end 9720 is adapted to interface with the airdelivery tube 4170. The tubular portion 9705 also comprises retentionand alignment features structured and arranged to align the intermediatecomponent 9700 with the reservoir dock 6050 and provide a removable,non-rotatable connection with the reservoir dock 6050. In addition, thetubular portion 9705 comprises a port 9730 (best shown in FIG. 120),e.g., for communicating with a sensor (e.g., pressure sensor) and/or amicrophone. In the illustrated example, the port 9730 is provided with aport seal and/or membrane 9735 to provide a sealing interface and/orcover between the port 9730 and a chassis opening 7380 (see FIG. 115C3)associated with the sensor and/or microphone. In an alternative example,the port 9730 may not include a port seal or membrane. Further, theintermediate component 9700 comprises retention features structured andarranged to provide a removable connection with the dock connector 4600of the air delivery tube 4170.

In the illustrated example (e.g., see FIG. 120), the tubular portion9705 (including the inlet end 9710, the outlet end 9720, and retentionand alignment features) comprise a first part or base mold constructedof a relatively rigid material (e.g., thermoplastic polymer (e.g., PC,ABS)) and the inlet seal 9715 and the port seal 9735 comprise a secondpart or overmold constructed of a relatively soft material (e.g.,thermoplastic elastomer (TPE) or silicone) that is provided (e.g., byovermolding) to the first part. The spatial separation of the softcomponents from the remaining hard material components of theintermediate component 9700 in FIG. 120 is only for illustrativepurposes—in practice the soft material components can be permanentlyattached to respective rigid components and the configuration of FIG.119 could be an integral intermediate component 9700 that cannot bedissembled into the individual components shown in FIG. 120.

In the illustrated example, the inlet end 9710 and inlet seal 9715thereof are arranged at an angle to the outlet end 9720, e.g., the axisof the opening at the inlet seal 9715 is arranged at about 90° withrespect to the axis of the opening at the outlet end 9720 (see FIG.119). However, it should be appreciated that other suitable angles arepossible, e.g., the axis of the inlet seal 9715 is arranged at about 45°with respect to the axis of the outlet end 9720.

When the water reservoir 6100 is coupled to the reservoir dock 6050, theinlet seal 9715 of the intermediate component 9700 is structured andarranged to engage and provide a face seal against a contact surfacealong the outlet end of the outlet tube 6130 (or outlet) of the waterreservoir 6100 (see FIGS. 131 and 132). Such engagement seals the outletflow path that allows humidified air to flow out of the water reservoir6100 and into the intermediate component 9700 for delivery to the airdelivery tube 4170. As illustrated, the inlet seal 9715 may comprise abellows-type arrangement that is resiliently compressible to provide acertain degree of decoupling between the intermediate component 9700 andthe water reservoir 6100.

In an alternative embodiment, the soft and/or flexible material sealbetween the outlet tube 6130 (or outlet) of the water reservoir 6100 andthe intermediate component 9700 may be an integral part of the outlettube 6130, or may be a sealing portion independent from either theoutlet tube 6130 or the intermediate component 9700.

The outlet end 9720 (e.g., see FIG. 115C3) may comprise an ISO taper,e.g., 22 mm outer diameter ISO taper, for coupling to the air deliveryconduit 4170.

In regards to retention and alignment features to align and retain theintermediate component 9700 to the reservoir dock 6050, the intermediatecomponent 9700 includes a resilient pinch arm 9740 (e.g. see FIGS.116-118), i.e., a cantilevered spring arm. The spring or pinch arm 9740may include a barbed end or tab 9745 structured to provide a snap-fitconnection with a locking member, e.g., cross-bar 9750, provided withinthe cavity of the reservoir dock 6050 (see FIGS. 112 and 114). Theintermediate component 9700 may also include a guide rail 9760 (along alower side of the intermediate component 9700) and a guide rib 9761(along a forward, upper side of the intermediate component 9700)structured and arranged to assist in correct alignment and insertion ofthe intermediate component 9700 into the reservoir dock 6050 byengagement with corresponding guide slots 9755 extending into the cavityof the reservoir dock 6050 (e.g., see FIGS. 114, 115B, 116, 117).

Further, the intermediate component 9700 includes a flange 9770 (e.g.see FIG. 116) arranged between the inlet end 9710 and the outlet end9720 to assist in locating and/or positioning the intermediate component9700, and more particular limiting the insertion depth of theintermediate component 9700 in the reservoir dock 6050. Flange 9770 doesthat by abutting a wall provided to the reservoir dock 6050, e.g.,flange acts as a stop during insertion as shown in FIGS. 115C3 and 115E.As shown in FIGS. 115D, 115E, and 120, one or more bumpers 9775 (e.g.,constructed of thermoplastic elastomer ((TPE) or silicone) can beprovided to soften abutment of the flange 9770 with the dock wall duringinsertion, and absorb vibrations in use. Apart from minimising thevibration of the intermediate component 9700, the flexible nature of thebumpers ensures that, once they are depressed, there is a resultantspring force that pushes backwards the barbed tab 9745 and ensures thatthe tab is in a constant locking engagement with the cross-bar 9750.This minimises any vibrations in the locking engagement between barbedtab 9745 and the cross-bar 9750, as well as the likelihood ofdisengagement. In the illustrated example, a first bumper 9775 isprovided to an upper side of the intermediate component 9700, and asecond bumper 9775 is provided to a lower side of the intermediatecomponent 9700 (see FIGS. 115D and 115E). In an example, the bumpers9775 may be attached to the dock wall or overmolded to the tubularportion 9705 along with the inlet seal 9715 and the port seal 9735 (seeFIG. 120).

In regards to retention features to retain the dock connector 4600 ofthe air delivery tube 4170 to the intermediate component 9700, theintermediate component 9700 includes a part-annular side wall 9790 (seeFIG. 120) that projects outwardly from the flange 9770 along the outletend 9720. As illustrated in FIG. 120, the outlet end 9720 and thepart-annular side wall 9790 cooperate to form an annular channel 9780for receiving the air delivery tube 4170. Each of the opposing innersides of the part-annular side wall 9790 includes a hole or recess 9792adapted to receive a respective retaining bump 4644 (see FIG. 123)provided to the dock connector 4600 of the air delivery tube 4170 duringengagement. In the illustrated example, a gap is provided in thepart-annular side wall 9790 (along a superior side thereof—see FIG. 120)to accommodate and facilitate the electrical connection of the dockconnector 4600 of the air delivery tube 4170.

Also, the intermediate component 9700 includes a lower tab 9795 (e.g.FIG. 120) that projects outwardly and downwardly from the part-annularside wall 9790 along a portion of the perimeter of the part-annular sidewall 9790 (along an inferior side thereof). The lower tab 9795 may actas a finger or push tab to facilitate insertion or retraction of theintermediate component 9700 into/from the reservoir dock 6050. Inaddition, the lower tab 9795 may be configured and arranged to cover orhide one or more fasteners 9799 (e.g., (screws) or edges between outershroud and chassis components of the integrated RPT device andhumidifier 6000 (see FIGS. 110 and 113).

When the intermediate component 9700 is inserted into the dock opening6091 of the reservoir dock 6050, the intermediate component 9700 isoriented to engage its guide rail 9760 and guide rib 9761 withrespective guide slots 9755 which correctly aligns and guides theintermediate component 9700 into an operative position (e.g., see FIG.113). Also, the dock opening 6091 and the part-annular side wall 9790 ofthe intermediate component 9700 include non-circular profiles tofacilitate correct orientation of the intermediate component 9700 duringinsertion.

The dimensions and the interaction between the intermediate component9700 and the reservoir dock 6050 may also be so arranged that the dockopening 6091 of the reservoir dock 6050, which opening receives theintermediate component 9700, may be of a cross-section that is slightlylarger than that of the intermediate component 9700 (e.g., see FIG.115C1). Closer to the end of the insertion path (e.g., see FIG. 115C2),however, there may be one or more bumpers, e.g. bumper 9751 and/orbumper 9752, providing elevation or bumper point(s) that elevates aninterior edge, or surface, 9758 of the intermediate component 9700(e.g., along the pinch arm 9740 and guide rail 9760) so that the entirefront end of the intermediate element 9700 is lifted. Because of that,the port seal 9735 may be moved into, or be made ready for, a sealingengagement with chassis opening 7380. Further insertion of theintermediate component can then bring a portion of the intermediateelement into an abutment engagement with a respective portion of thechassis opening, preventing further insertion. At this point the portseal 9735 of the port 9730 is moved into the sealing engagement with thechassis opening 7380 (e.g., see FIG. 115C3), or is arranged to preservethe sealing engagement, if such an engagement had already been formed.As shown in FIG. 115C, the tab 9795 may include a rib or bumper 9753providing an additional elevation or bumper point arranged to interfacewith the dock. The above described arrangement would minimise thefriction during insertion of the intermediate element into the dockopening 6091, whilst still ensuring the sealing engagement between theport seal 9735 and the chassis opening 7380 in the engagedconfiguration. Because of the large forces that may be applied to theintermediate element 9700 during use, more than one bumper points may beused (such as elevation points at bumpers 9751 and 9753, or elevationpoints at bumpers 9751, 9752 and 9753) for increased stability. Theinclusion of such multiple support/elevation points may help ensuring arobust and consistent seal at 9730 even where the patient may pull onthe tube during therapy. Additionally, the robust support of theintermediate element enables easier attachment and removal of attachedtubes to the intermediate element.

When the intermediate component 9700 reaches an operative position, thebarbed end or tab 9745 of the spring or pinch arm 9740 is configured andarranged to engage under and behind the cross-bar 9750, e.g., see FIG.112. The barbed end 9745 and/or the cross-bar 9750 may include a taperto facilitate engagement into the operative position. In an example, theengagement of the spring or pinch arm 9740 with the cross-bar 9750 mayprovide sensory feedback, e.g., audible click, to indicate correctionconnection. This snap-fit connection releasably secures the intermediatecomponent 9700 to the reservoir dock 6050. To disengage the intermediatecomponent 9700, the spring or pinch arm 9740 can be manually depressedtowards the back of the reservoir dock 6050 (e.g., with or without atool). Such pressure resiliently flexes the spring or pinch arm 9740 andbarbed end 9745 into an unlocked position, i.e., where barbed end 9745is moved out of engagement with the cross-bar 9750 to allow theintermediate component 9700 to be removed from the reservoir dock 6050.

Once the intermediate component 9700 is inserted and locked into thedock opening 6091 of the reservoir dock 605, the cooperating retentionand alignment features provided by the intermediate component9700/reservoir dock 6050 provides a removable, non-rotatable connectionof the intermediate component 9700 to the dock outlet 6090 of thereservoir dock 6050. Also, once connected, the spring or pinch arm 9740of the intermediate component 9700 is lockingly engaged within thecavity of the reservoir dock 6050, e.g., to prevent removal of theintermediate component 9700 when the water reservoir 6100 is received inthe reservoir dock 6050.

When the intermediate component 9700 is connected to the dock outlet6090 of the reservoir dock 6050, the inlet seal 9715 thereof protrudesinto the cavity of the reservoir dock 6050 to allow engagement with theoutlet tube 6130 (or outlet) of the water reservoir 6100 (see FIG. 112and FIG. 131). Likewise, the outlet end 9720, along with thepart-annular side wall 9790 and holes 9792 thereof, extends withinand/or protrudes out of the cavity of the reservoir dock 6050 to allowengagement with the air delivery tube 4170, e.g., see FIGS. 110 and115A. Further, the port 9730 and port seal 9735 thereof, are oriented,e.g., upwardly as shown in FIG. 115C3, to interface with the chassisopening 7380 associated with the sensor and/or microphone.

Electrical Connection

As shown in FIGS. 110, 115A, 121, and 122, an electrical contactassembly 9950 is provided to the dock outlet 6090 of the reservoir dock6050 to electrically connect the reservoir dock 6050 to the air deliverytube 4170 and form electrical (both power and control signal)connections.

As best shown in FIGS. 121 and 122, the contact assembly 9950 issupported by the reservoir dock 6050 along a superior side of the dockopening 6091 at the dock outlet 6090 of the reservoir dock 6050. Thecontact assembly 9950 is in communication with electrical power andelectrical signalling within the reservoir dock 6050, e.g., the PCBA7600. As illustrated, the contact assembly 9950 includes a supportmember 9952 and a plurality of contacts 9955, e.g., four contacts,supported by the support member 9952. Each of the contacts 9955 cancomprise a spring arm 9956 (as best seen in FIG. 122) that is biasedaway from the support member 9952. In use, when the dock connector 4600of the air delivery tube 4170 engages with the reservoir dock 6050, thespring arms 9956 will resiliently deflect during engagement with thedock connector 4600 to maintain contact with respective contacts 4667 ofthe dock connector 4600. The contact assembly 9950 also includes anelectrical connector 9958, e.g., flexible circuit board (FCB), flexibleprinted circuits (FPC) and/or flexible flat cables (FFC), toelectrically connect the contacts 9955 to the PCBA 7600 (see FIG. 122).

As shown in FIGS. 110 and 115A, an external housing or outer shroud 8050(enclosing the chassis assembly 7300 and reservoir dock 6050) provides acover or enclosure for the contact assembly 9950, and forms a socket oropening 9980 leading to the contacts 9955 (female connector) forengagement with respective contacts of the dock connector 4600 (maleconnector).

Dock Connector

As shown in FIGS. 110-111, the dock connector 4600 of the air deliverytube 4170 is structured to form a pneumatic and mechanical connectionwith the intermediate component 9700 and form an electrical connectionwith the contact assembly 9950 provided to the reservoir dock 6050.

In the illustrated example, the dock connector 4600 includes a tubularbase portion 4640 and a contact assembly 4661 provided to the baseportion 4640 (see FIG. 110).

As shown in FIGS. 123-126, the tubular base portion 4640 includes aradial lip seal 4645 that protrudes into the inlet opening of the baseportion 4640. The radial lip seal 4654, in its relaxed, undeformedshape, provides an internal diameter that is smaller than the externaldiameter of the outlet end 9720 (FIG. 115A) of the intermediatecomponent 9700 with which the dock connector pneumatically engages. Forexample, the internal diameter provided by the radial lip seal 4645 maybe less than about 22 mm (e.g., about 19-21 mm or less) for use with anoutlet end 9720 comprising a 22 mm outer diameter ISO taper. In use, theradial lip seal 4645 is structured to resiliently deform upon engagementwith the outlet end 9720 of the intermediate component 9700 so as toprovide a pneumatic connection with the intermediate component 9700,e.g., radial lip seal 4645 forms a gas tight seal around and against theexterior surface of the outlet end 9720 of the intermediate component9700. As best shown in FIG. 125, the radial lip seal 4645 extends at anangle towards the interior of the base portion 4640 to provide a lead infor aligning and engaging the dock connector 4600 with the intermediatecomponent 9700. Also, a stop surface 4647 (see FIG. 125) within the baseportion 4640 provides a stop to prevent the intermediate component 9700from being inserted further into the dock connector 4600.

A tapered protrusion 4642 protrudes outwardly from the base portion 4640(see FIG. 123) adjacent the contact assembly 4661. The taperedprotrusion 4642 provides a thumb and/or finger grip to facilitate manualmanipulation and connection of the dock connector 4600 with theintermediate component 9700 and the contact assembly 9950 provided tothe reservoir dock 6050. As shown in FIG. 111, the tapered protrusion4642 may include an alignment marking that is configured and arranged toalign with an alignment marking provided to the reservoir dock 6050 whenthe air delivery tube 4170 is connected to the reservoir dock 6050, toensure correct alignment and proper connection of the dock connector4600 of the air delivery tube 4170 to the reservoir dock 6050 in use.

Further, as best shown in FIG. 123, the base portion 4640 includes aresilient retaining bump 4644 on each of the opposing sides of the baseportion 4640. As described below, the retaining bumps 4644 arestructured and arranged to interact with respective holes 9792 providedto the intermediate component 9700 during engagement, so as to retainthe dock connector 4600 in operational engagement with the intermediatecomponent 9700 and, thus, with the entire RPT device 6000.

As shown in FIG. 123, the contact assembly 4661 (lead frame) includes asupport portion 4665 and a plurality of contacts 4667, e.g., fourcontacts, included along a front side of the support portion 4665. Asillustrated, the support portion 4665 includes a step-shapedconfiguration to support the contacts 4667 in spaced relation from thebase portion 4640. The contacts 4667 are arranged to engage withrespective contacts 9955 provided to the contact assembly 9950 on thereservoir dock 6050 to form electrical and control signal connectionswith the reservoir dock 6050. In the illustrated example, the contacts4667 are arranged as a male connector configured to form the electricaland signal connections when inserted into engagement with the contacts9955 arranged as a female connector on the reservoir dock 6050, i.e.,straight or direct plug-in connection. The support portion 4665 providesan electrical connector to electrically connect the contacts 4667 torespective wires running along the air delivery tube 4170 and/or circuitelements.

As shown in FIG. 123, the tracks of the contacts 4667 are elevated(spaced away from the main body of the cuff) and extend in an axialdirection which allows them to initiate and maintain the electricalconnection when the dock connector 4600 is inserted into the socket 9980in which the contacts 9955 are arranged. However, it should beappreciated that the support portion and/or the contacts may havealternative configurations and arrangements, e.g., depending on theinterface arrangement or connection mechanism provided at the dockoutlet 6090 of the reservoir dock 6050.

In the illustrated example, as shown in FIG. 126, the dock connector4600 may comprise a base assembly 4680 (including a base 4682 and acover 4684) that supports the contact assembly 4661 (lead frame). In anexample, the contact assembly 4661 may first be engaged or interlockedwith the base 4682, and then the cover 4684 may be clipped onto orotherwise engaged with the base 4682 to securely support and retain thecontact assembly 4661 in an operative position. The base assembly 4680is constructed of a relatively rigid material (e.g., thermoplasticpolymer (e.g., PP, PC, ABS)) and an overmold 4690 constructed of arelatively soft material (e.g., thermoplastic elastomer (TPE) orsilicone) is provided (e.g., by overmolding) to the base assembly 4680.As illustrated, the relatively rigid base assembly 4680 may form thestructural shape for the tubular base portion 4640, the taperedprotrusion 4642, and resilient retaining bumps 4644 while the relativelysoft overmold 4690 forms the soft exterior for the tubular base portion4640 and the tapered protrusion 4642 and forms the radial lip seal 4645.

Engagement of Dock Connector with Reservoir Dock

FIGS. 110-111 and 127-130 illustrate engagement of the dock connector4600 of the air delivery tube 4170 with the reservoir dock 6050. Asshown in FIG. 110, the dock connector 4600 is oriented to align itscontact assembly 4661 with the socket 9980 leading to the contactassembly 9950 on the reservoir dock 6050. The dock connector 4600 isthen pushed axially towards the reservoir dock 6050 so that the outletend 9720 of the intermediate component 9700 extends into the opening ofthe base portion 4640 and the radial lip seal 4645 engages andresiliently deforms against the exterior surface of the cylindricaloutlet end 9720. The radial lip seal 4645 of the dock connector 4600engages and slides along the exterior surface of the outlet end 9720 ofthe intermediate component 9700 as the dock connector 4600 is pushedfurther towards the reservoir dock 6050 until it reaches a lockedposition, wherein the contact assembly 4661 extends into the socket 9980to engage the contacts 4667 with respective spring arms 9956 of thecontacts 9955 which forms the electrical and control signal connectionswith the reservoir dock 6050 (see FIGS. 111 and 129-130).

Moreover, when the dock connector 4600 reaches the locked position, thebase portion 4640 of the dock connector 4600 is received within thechannel 9780 formed by the intermediate component 9700 and the retainingbumps 4644 are configured and arranged to engage within respective holes9792 provided to the part-annular side wall 9790 of the intermediatecomponent 9700 to releasably retain the dock connector 4600 in thelocked position under operational pressure (see FIGS. 127-128). Suchengagement of the retaining bumps 4644 within respective holes 9792 mayprovide tactile feedback during engagement. In the locked position, thedock connector 4600 is pneumatically and mechanically engaged with theintermediate component 9700 and electrically connected to the electricalcontacts of the reservoir dock 6050.

Also, as shown in FIGS. 123, 125 and 126, the dock connector 4600 mayinclude one or more internal ribs 4648 configured to engage along theexterior surface of the outlet end 9720 of the intermediate component9700 to help locate and align the dock connector 4600 with respect tothe intermediate component 9700.

In an example, the forward end of the base portion 4640 may engage theflange 9770 of the intermediate component 9700 and/or a stop surface9647 within the base portion 4640 may engage the free end of the outletend 9720 of the intermediate component 9700. The abutment prevents thedock connector 4600 from inserting further into the socket 9980 and theintermediate component 9700 and acts as a stop during insertion (seeFIGS. 127-130).

In an example, connection of the dock connector 4600 with the reservoirdock 6050 is configured so that the pneumatic connection is completedprior to the electrical and mechanical connections. In an example, theelectrical and mechanical connections may be formed simultaneouslyfollowing the pneumatic connection, or the electrical and mechanicalconnections may be formed in series following the pneumatic connection.In another example, the pneumatic, electrical, and mechanicalconnections may be formed simultaneously when the dock connector isinserted into the locked position.

To remove the air delivery conduit 4170 from the reservoir dock 6050,the dock connector 4600 may be pulled outwardly away from the reservoirdock 6050 with sufficient force to release the retaining bumps 4644 fromrespective holes 9792.

Tube Identification Examples

FIG. 35A shows a schematic view of a dock and a tube connection inaccordance with one form of the present technology. The dock outlet 6090may include a contact assembly 6800 that can be coupled to acorresponding contact assembly 4172 of the tube 4170 via fourconnections. The dock outlet 6090 may be mechanically and electricallycoupled to the tube 4170.

As shown in FIG. 35A, the contact assembly 6800 includes fourconnections that are coupled to processing circuitry, e.g., PCBA 7600.Two of the connections (Heater+ and Heater−) are coupled to a heatercontrol circuit and two of the connections (+SENSOR and −SENSOR) arecoupled to a sensing circuit. In some examples, the +SENSOR and −SENSORconnections may be coupled to an NTC sensor. In some examples, thesensing circuit may also be connected to the connections (Heater+ andHeater−). The heater control circuit and the sensing circuit may beincluded in the humidifier, e.g., PCBA 7600.

The heater control circuit may supply power to heating element in thetube 4170 via a switch (e.g., a transistor). The heater control circuitmay control the duration, voltage, and/or frequency and/or period ofPulse Width Modulation (PWM) signal supplied to the heating elements inthe tube 4170.

The sensing circuit may be configured to receive signal(s) from atransducer (e.g., negative temperature coefficient (NTC) thermistor)disposed in the tube 4170, indicative of the operation of the heatingelements in the tube 4170. The transducer may be disposed at the maskproximal end) of the tube.

For example, the sensing circuit may measure voltage and/or current ofthe transducer to determine the operating characteristics (e.g.,temperature) of the heating elements. The heater control circuit maycontrol the heating elements based on the signals received by thesensing circuit and the settings sets for the heating tube 4170. Othersensors disposed anywhere in the tube, i.e., humidity sensors, may alsobe connected in a similar way.

The sensing circuit may automatically identify the type of tube 4170connected to the dock 6050. The type of tube that is connected to thedock 6050 may be determined by the sensing circuit based on uniqueelectrical characteristic(s) provided by active and/or passivecomponents in the tube 4170 via one or more of the four electricalconnectors 6805. Based on the indicated type of tube 4170 connected tothe dock, a controller may change the operating parameter of the system.For example, different heating control settings may be provided fordifferent tubes (e.g., non-heated tube, heated tube, tube with heat andmoisture exchanger (HME), tube unknown). In some example, the settingsmay be modified based on the size of the identified air delivery tube(e.g., 15 mm, 19 mm), presence and type of HME, type of patientinterface connected to tube, etc. The type of tube that is connected tothe dock 6050 may be determined by the sensing circuit based on uniqueelectrical characteristic(s) provided by active and/or passivecomponents in the tube 4170 via one or more of the four connectors.

As shown in FIG. 35A, the tube 4170 includes four connections forcoupling to respective four connections in the contact assembly 6800.The connections in the tube may be solid pins (as shown in FIG. 24A),but are not so limited. In some examples, the connections may beprovided by, for example, leadframe terminals. In one example, when thetube 4170 is connected to the dock, solid pins in one of the devicesconnect to corresponding pogo pins in the other device (e.g., see FIG.20J).

As shown in FIG. 35A, a first circuit element 8022 is coupled to twopins in tube 4170 and a second circuit element 8024 is coupled to twoother pins in the tube 4170. While single circuit elements are shown inFIG. 35A, first and/or circuit elements may include a plurality ofactive and/or passive circuit elements.

The first circuit element 8022 may include the heater elements in thetube 4170 and/or one or more other elements. The first circuit element8022 may represent the resistance of the heater elements.

The second circuit element 8024 may include a sensor in the form of athermistor formed of a Negative Temperature Coefficient (NTC) material.The parameters of the second circuit element 8024 (e.g., resistance) maychange with a change of tube temperature. The sensing circuit may beconfigured to sense the temperature of the tube 4170 by monitoringchanges in the parameters of the second circuit element 8024.

FIG. 35B shows circuit diagram of the dock and tube connection inaccordance with one form of the present technology. The first circuitelement 8022 in FIG. 35A may be represented by two resistors 5R (withapproximately 5 ohms) coupled to the Heater+ and Heater− connections.This is associated with the fact that the heating wire usually comprisesone or more (usually two) copper wires connected sequentially to eachother and having a total resistance of about 10 ohms. The combinedlength of wire extends from the dock coupling end of the tube to themask coupling end of the tube and back to the dock coupling end of thetube. The second circuit element 8024 in FIG. 35A may be represented bya thermistor and two resistors 5R coupled to the NTC+ and NTC−connections. The thermistor in FIG. 35A may be selected based on thetype of air tube. A 10 k thermistor may be provided in a 15 mm air tube,a 100 k thermistor may be provided in a 19 mm air tube, and an opencircuit may be provided in a passive air tube.

The heating wires 8022 are usually distributed along the length of thetube and the sensor 8024 is usually positioned at the mask end of thetube. Thus, both the heating wires and the sensor connecting wiresextend the length of the tube.

The first and second circuit elements may be used by the sensing circuitto identify the type of tube connected to the dock 6050. In someexamples, unique electrical characteristic of one or more contact pinsmay be used to identify parameters of the tube. The different resistancevalues provided by the first and second circuit elements may allow forthe control circuit in the humidifier to determine the type of tube thatis connected and which control parameters to use for the operation ofthe system. The sensing circuit may measure the resistance of the firstcircuit element and/or the second circuit element to determine the typeof tube. Alternatively, further electrical pins (in addition to the fourpins illustrated in FIGS. 35 and 36) may be included in the dockconnector 4600 of the air delivery tube 4170, which are associated witha unique characteristic (such as electrical resistance) and may be usedto indicate parameters such as the type, as well as othercharacteristics associated with the tube.

As an example, the different type of tubes may include: (1) a 4-wire 15mm heated tube may provide a Heater Wire resistance of 2×5R and a NTCresistance value at 25° C. is 10K; (2) a 4-wire 19 mm heated tube mayprovide a Heater Wire resistance is 2×5R and NTC resistance value at 25°C. is 100K; and (3) a passive non-heated tube may be provided with astandard ISO-taper.

Thus the detection of the connected tube type is performed by measuringthe second circuit element (e.g., NTC) and the first circuit element(e.g., Heater Wire) resistance combinations (in cases (1) and (2)above), detecting the electrical characteristics of one or moreindependent pins or a combination of such, or detecting the open circuiton both pairs of connections (case (3) above).

The system may also be configured to automatically detect a single faultconditions in the connected active tube, for example short or opencircuit on any of the four tube wires, as well as the non-legit value(partial crack) of the Heater Wire, as well as cross-short circuitbetween the tube wires.

Examples of the present technology provides not only for direct couplingof a tube to the dock, but also for an electrical adapter. While such anadaptor may allow the connection to the dock of different types ofheated wire tube, its main purpose is to facilitate the coupling to thedock of a passive air tube capable of operating with or without HMEpassive humidifier at the proximal end. The two main applications forusing such adapter are: (a) allowing the mechanical connection ofpassive air tubes to the dock and (b) providing the means for the systemto detect the passive air tube.

FIG. 36 shows a schematic view of a dock and a tube connection inaccordance with the above discussed form of the present technology. Asshown in FIG. 36, the contact assembly 6800 of the dock may be coupledto a passive tube 4170 via an adapter 8020. The adaptor 8020 provides anelectrical connection, which is generally not present in the passivetube 4170, to the contact assembly 6800 of the dock. In one example, thetube 4170 may provide a mechanical connection to the dock 6050 and thetube adaptor 8020 may provide the electrical connection. In someexamples, the tube adaptor 8020 may also mechanically couple to thedock. FIGS. 24A-24B illustrate a mechanical connection of the tube 4170and a tube adaptor 8020 in accordance with one form of the presenttechnology.

In some examples, the adaptor 8020 may be part of a contact assembly.The adaptor 8020 may be manufactured as an integral part of the tube4170 or be removable from the tube 4170. In this manner air tubes thatdo not have electrical components, such as heating elements and/orsensors, may be provided with circuit elements to identify the kind ofair tube that is connected to the dock 6050.

In contrast to FIG. 35A including the first and second circuit elements8022 and 8024 in the tube 4170, the example shown in FIG. 36 includesthe first and second circuit elements 8022 and 8024 in the adapter. Onlyin this case these circuit elements do not represent the resistance of aheater wire and of a NTC sensor/transducer, but include simple resistorsthat are detected by the controller in order to identify the connectionof a passive tube to the system. As shown schematically in FIGS. 24A-B,the first and second circuit elements 8022 and 8024 may be provided in ahousing including the connections. The first and second circuit elements8022 and 8024 may directly connect to the connections provided in theadaptor 8020. In one example, the first circuit element 8022 includes asingle resistor which is directly coupled to two of the connections inthe adapter of the tube, and the second circuit element 8024 includes asingle resistor which is directly coupled to two other connections inthe adapter of the tube. In some examples, the adaptor 8020 may beprovided outside of the tube and/or surrounding the tube. In thisexample, the first and second circuit elements are provided on theexternal surface of the tube and/or the tube connector.

The first and second circuit elements in the adapter allow for thesensing circuit in the humidifier to determine the type of tubeconnected to the dock 6050. This is different from the example in FIG.35A, where characteristics of circuitry including the heating elementand/or the sensor (e.g., provided in the tube) are used to determine thetype of type connected to the system. Because of that, the value of thefirst and second circuit elements in this example of a passive tubeneeds to be selected so that it is outside of the range of values thatwould be expected from first and second circuit elements of the activetube in FIG. 35A. As would be discussed below, the specific electricalcharacteristics (i.e., resistance) of the NTC element has to beconsidered in working environment where it may spread over a broad rangeof values.

FIG. 37 shows a schematic view of a tube NTC resistance variations overdifferent temperatures for a 100 k thermistor (usually used with a 19 mmheated tube) and a 10 k thermistor (usually used with a 15 mm heatedtube). The 100 k thermistor and a 10 k thermistor may correspond to thethermistor that may be included in the second circuit element 8024 shownin FIG. 35A. The present technology is based on using the resistorconnected to NTC terminals of an adaptor, which is distinctly differentfrom that of the real NTC resistances at legitimate areas of operation.As seen in FIG. 37, the area between approximately 27 Kohm and 51K isnot used by the 10 k and 100 k NTC during normal operation, so theresistor used in the tube (or adaptor as discussed below) can beselected to be at 36K or thereabout. Accordingly, when a tube with anadaptor having a second circuit element 8024 resistance value of 36 k isconnected, the system will know that the tube is not the 15 mm tubeusing the 10 k thermistor nor the 19 mm tube using the 100 k thermistor.Whilst such atypical value resistance was described above as indicatingthe use of a passive tube with an adaptor, the specific resistance ofone or more electrical pins may be used to indicate a variety of otherparameters associated with the tube or even the mask, in a tube-masksystem. Such parameters may include the presence or absence of HME inthe tube/mask, the type of mask attached to the tube (nasal or fullface) etc.

To reduce the possibility of the false detection (in case, for example,when 15 mm heated tube is exposed to the sun and gets heated to 50° C.and then gets immediately connected to the dock), the first circuitelement 8022 is used in the adapter, which connects the Heater+ andHeater-terminals together through the resistance of a predeterminedvalue (e.g., approximately 1 Kohm). A 1 kohm resistance can conductmaximum 24 mA of current (at 100% PWM) which is only dissipating 0.6 Wpower but is enough to be reliably measured by dock subsystem circuit.

Using two circuit elements (e.g., resistors) as described above in theadapter practically eliminates the possibility of misdetection of theconnected tube while keeping the system safe. Using the resistorsprovides for a low cost identification system with accurateidentification. Other circuit elements (e.g., resistors, capacitorsetc.) may be provided in parallels and/or series with the first and/orsecond circuit elements to provide characteristics that are distinctfrom characteristics of other circuits used for identification.

FIG. 38 shows a schematic view of a dock and a tube connection inaccordance with another form of the present technology. The exampleshown in FIG. 38 is similar to the example shown in FIG. 36, but onlyuses a single circuit element (e.g., 36K resistor) in the adapter toreduce the cost of goods in the adapter. In this example, in addition toreducing the number of circuit elements, the number of connections inthe adapter are also decreased. The reliability of the detection may besomewhat diminished, as the combination of 36K value of NTC and opencircuit of the Heater wire may also represent the situation of eitherdouble fault in the tube (NTC partial crack on NTC wire+open circuit onheater wire) or the case of the contaminated NTC terminals with thepassive tube connected mechanically via ISO taper.

FIG. 39 shows a dock and a tube connection in accordance with anotherform of the present technology. In this example, a part of the PWM whichis provided to the heating elements, is “injected” into the NTCdetection circuit. This signal is detected by the microcontroller viathe comfort subsystem NTC measurement circuit. Because the detectedsignal is distinctly different from all standard modes of operation ofother tubes discussed above, this example may present the bestdetectability. However, this configuration may be undesirable in someimplementations because it uses the undesirable functional interactionbetween two different parts of the circuitry (+24 PWM heating and +3V3NTC detection) that logically should not be functionally connectedtogether.

While the above examples of the present technology have been describedwith reference to a four wire system, the examples are not so limited.The examples of the present technology may be applied to systems withother number of wires, e.g., two wires, three wires, or five or morewires. Also, whilst the above embodiments were mostly described withrespect to detecting the type (size) of tube attached to the system, thevariation in electrical parameter values described in relation to FIGS.35-39, may be used to not only indicate various parameters associatedwith the tube (e.g. the type (heated/non-heated) and size (15 mm or 19mm)) but also of parameters associated with the mask used. For example,the variation in electrical parameters may be used to indicate one ormore of the following mask parameters; the type of the mask attached tothe tube (nasal or full face), the mask size (small, medium, large), thepresence or absence of HME in the tube or the mask etc.

Wire Cross-Talk

As noted above, the air delivery tube 4170 according to an example ofthe present technology may comprise four wires, e.g., two wires forheating elements and two wires for a transducer, e.g., negativetemperature coefficient (NTC) thermistor used as a temperature sensor.It should be noted that NTC is only one of a plurality of differenttypes of temperature sensors known to a skilled addressee.

An aspect of the present technology relates to reducing or eliminatingcross-talk between wires, e.g., to enhance accuracy of the signaltransmission provided by the NTC thermistor.

FIG. 40 shows a schematic view of a tube with a four wire circuitcoupled to a dock in accordance with one form of the present technology.In the four wire circuit, resistors 9010 and 9012 represent resistanceof the one or more heating element/s and resistors 9020 and 9022represent the resistance of the wires coupled to a sensor 9030. FIG. 40is a schematic representation and the fact that two set of resistors 910and 912 are shown does not necessarily mean that there are two or moreheater wires. A single continuous heating wire or more than two wiresmay also be used in the discussed heated tubes. For example, thetwo-wire arrangement shown in FIG. 40 has four connections formedbetween the dock and the tube. PWM and GND connections are coupled tothe heating element/s and VH and VL are coupled to the sensor 9030. Thecapacitance elements C shown in FIG. 40 are not actual capacitors, butrepresent the distributed parasitic capacitive coupling between twowires (i.e. between the heater wire 9010 and the resistor wire 9020)located in close proximity.

For the heating element/s, the power is supplied via connections PWM andGND and may be regulated by a Pulse Width Modulator (PWM). The PWMsignal creates an AC signal. Certain settings (e.g., pulse frequency) ofthe PWM signal may cause the heating element wires to move/vibrate(which can be audible) due to electromagnetics (EM). To prevent hearingthe movement of the wires, the pulse frequencies of the PWM signal maybe set at and/or above a predetermined value (e.g., at or above 20 KHz).

The sensor 9030 may be a transducer (e.g., a negative temperaturecoefficient (NTC) thermistor) disposed in the tube 4170 for measuringthe heat in the tube 4170. As discussed above, the sensor 9030 may havedifferent characteristics (e.g., nominal resistance values of 10K or a100 k) to identify different types of tubes. At room temperature thesensor 9030 may have a resistance value (e.g., tens of K Ohms) that issignificantly larger than a resistance of wires (e.g., 5 Ohms) connectedto the sensor. 9030.

As shown schematically in FIG. 42, voltage Vsense is provided to thesensor 9030. The voltage is provided by the microcontroller via adivider network comprising a first resistor RHigh and a second resistorRLow. The sensor 9030 is coupled with the two resistors RLow and RHighso that, upon failure of one of the wires, the system can detect whichwire failed. A DC voltage is applied to the divider network fordetecting the operating parameters of the sensor 9030 and/or failure ofone of the wires. The combination of measured voltages at the VLow andVHigh terminals would indicate to a skilled addressee whether an NTCwire is shortened with another NTC wire, or with a heater wire, and alsowith which exactly heater wire. For example, an NTC wire shortened withan NTC wire the microcontroller will measure a zero voltage difference.On the other hand, if the NTC wire has short-circuited with a PWM heaterwire, the measured voltage difference will be larger than Vsense (theVsense DC voltage is usually about 3.3V, whilst the PWM AC voltage isabout 24V).

In operation, when the PWM pulse is turned on, the PWM wires arecapacitively connected (see capacitors C in FIG. 40) to the wires of thesensor 9030. The AC signal penetrates through the parasitic (inherent)capacitors into the sensor 9030 wires. FIG. 41 shows a signal diagram ofa PWM signal that may be applied to the heating elements (Signal (A) or(B)) and the portions of the PWM induced signal that may be observed inthe sensing circuit (Signal (C)).

The signal at VH (V high) and VL (V low) points is provided to themicrocontroller configured to subtract the V low from the V high. Thedifference between the V low and V high indicates the resistance of thesensor 9030. The microprocessor is configured to track the changes inresistance of the sensor 9030 due to changes in the temperature of thetube 4170 and determine operation setting for components of the system(e.g., heating elements in the tube 4170).

The probing of the sensor 9030 (e.g., by a microprocessor) may be timedat intervals that are not synchronized with the PWM signal. In someexamples, the probing of the sensor 9030 is slower than the period ofthe PWM signal. In some instances, the probing period may be severalseconds. The probing period may change depending on the circumstances.For example, in some instances the probing may be constant, whilst inothers, a probing of several seconds may be used for the time periodswhen it is detected that there is no tube connected to the dock, howevera shorter period, or even a continuous monitoring, may be used once itis detected that there is a tube connected to the device. As discussedabove, the signal for probing the sensor 9030 is provided as a DCsignal.

Because of the slow probing of the sensor 9030, the sensing circuit cancatch different portion of the fast PWM induced signal (see graph (c) ofFIG. 41). The induced signal may be 10-20 percent of the voltage of thesensor 9030 signal. The setting of the PWM signal and changes in the PWMsignal may affect the accuracy of the measurement based on the voltageof the sensor 9030 signal. The temperature error caused in the sensingcircuitry may be up to 5 degrees (in a measured range of 5 to 40degrees).

To address these issues, in accordance with one form of the presenttechnology, high pass electrical filters are provided between the NTCoutput Vhigh and Vlow points and ground, to remove the high frequencycomponents of the signal (those of PWM frequency and above) in thecircuitry including the sensor 9030. As shown in FIG. 42, a first highpass filter HPF1 is coupled to the RHigh resistor and ground, and asecond high pass filter HPF2 is coupled to the Rlow resistor and ground.Alternatively, or in addition to the above, low pass electrical filters(e.g., LPF3 and/or LPF4) can be provided between the NTC output Vhighand Vlow points and the microcontroller. As shown in FIG. 42, a firstlow pass filter LPF1 is coupled to the RHigh resistor and connectionVH-Lpf and a second low pass filter LPF2 is coupled to the Rlow resistorand the connection VL-Lpf. Each filter may be formed as a singlecomponent (i.e., a capacitor) or a combination of active (i.e.,operational amplifiers) and/or passive (resistor/capacitors) electroniccomponents. For example, when a large capacitor (tens of nF) is used foreach of LPF1 and LPF2, the cross-talk between the wires of the heatedtube and the sensor is largely mitigated even without the use of LPF3and/or LPF4. However, if smaller capacitors (i.e., tens of nF) are usedinstead for LPF1 and LPF2, these two filters are now more useful forremoving external interferences of larger frequencies, but may notmitigate the cross-talk efficiently. This can be compensated with theintroduction of LPF3 and LPF4 which may be configured to filterfrequencies near the frequencies of the pulse width modulated powersignal and frequencies higher than the frequencies of the pulse widthmodulated power signal.

The sensor 9030 supply (for the divider) Vsense can be turned on and offto detect if the tube 4170 connected. When the tube 4170 is notconnected, the supply to the sensor 9030 can be turned off. Turning offthe supply may reduce corrosion in the connections.

In accordance with one form of the present technology, the sensor 9030supply (for the divider) Vsense is generally turned off, but is turnedon and off periodically to detect if the tube 4170 is connected. When itis detected that the tube 4170 is not connected, the supply to thesensor 9030 is turned off again. Turning off the supply may reducecorrosion in the connections in the humid environment in which they maybe operating. During the short periods the tube is intermittently turnedon, the check on whether the tube has been attached, is conducted byprobing Vhigh and Vlow. If Vhigh=Vsense and Vlow=0, the tube is notconnected. If the tube has been connected, because of the voltagedivider defined by RH and RL, Vhigh and Vlow change to respectivevoltages that are within a predetermined range. When the tube isdetected, Vsense is switched on permanently and VH and VL are used tomeasure the temperature.

The turning on and off of Vsense may be controlled to happen atintervals that are greater than the period of the PWM signal applied tothe heating elements. In one example, the frequency of the PWM signalmay be 20 KHz (T=50 μs) and the Vsense is turned on and off every 1, 2,or 3 seconds (1 to 0.333 Hz). If other, including non-periodical, timeranges are employed for the intermittent turning on of Vsense, to effectthe probing for the connection of the heated tube, they are likely to beof similar frequency range. Therefore, the filter may be configured tofilter out the cross-talk (20 KHz), but keep the 1 second transientsfrom the on and off operation, and any fast changes in the sensor 9030(e.g., an open window). In one example, the filter may be configured tofilter out everything above several Hz. In other examples the filter mayfilter everything above any one chosen frequency in the frequency rangeof 1 to 100 Hz.

5.6.2.3 Water Level Indicator

The water reservoir 6100 may comprise a water level indicator. In someforms, the water level indicator may provide one or more indications toa user such as the patient 1000 or a care giver regarding a quantity ofthe volume of water in the water reservoir. The one or more indicationsprovided by the water level indicator may include an indication of amaximum of a predetermined volume of water, as well as any portionsthereof, such as 25%, 50% or 75%, or volumes such as 200 ml, 300 ml or400 ml.

In an example, a heating element may be internally suspended within thewater reservoir 6100, e.g., heating element provided within chamber ofwater reservoir 6100 to directly heat water rather than heat water viaheat transfer through conductive portion 6150 of water reservoir 6100.In an example, the heating element may be vertically suspended by thereservoir lid 6114.

In the above example, the heating element may be subdivided orpartitioned into vertically distributed zones/sections. Each of thezones/sections may be controlled independently to independently switchon/off and control the temperature of each of the zones/sections and todeactivate when not heating (i.e., when water level has dropped and anupper portion of the heater is no longer in contact with water). Thiscan lead to an efficient use of energy to only heat the zones/sectionsthat are in contact with water. Also, each of the zones/sections may beassociated with a respective sensor. The distribution in verticaldirection of a number of sensors (such as NTC-type sensors) allowsdetecting the water level to provide an indication to the patientregarding a quantity of the volume of water in the water reservoir,e.g., without the patient having to directly view the water level in thewater reservoir. Such arrangement may allow the use of a water reservoirhaving non-transparent side walls, e.g., non-clear plastic or metal sidewalls, as the water level does not need to be directly viewed through aside wall of the water reservoir.

In some cases, the heating element may include a PCB with printedresistive tracks. Such an arrangement allows for easy partitioning ofthe track, thus defining different heating zones. A verticallyorientated distributed temperature sensor or a number of discretesensors, may be used to indicate if a level is inside water or not.

5.6.2.4 Humidifier Transducer(s)

The humidifier 5000 may comprise one or more humidifier transducers(sensors) 5210 instead of, or in addition to, transducers 4270 describedabove. Humidifier transducers 5210 may include one or more of an airpressure sensor 5212, an air flow rate transducer 5214, a temperaturesensor 5216, or a humidity sensor 5218 as shown in FIG. 5G. A humidifiertransducer 5210 may produce one or more output signals which may becommunicated to a controller such as the central controller 4230 and/orthe humidifier controller 5250. In some forms, a humidifier transducermay be located externally to the humidifier 5000 (such as in the aircircuit 4170) while communicating the output signal to the controller.

5.6.2.4.1 Pressure Transducer

One or more pressure transducers 5212 may be provided to the humidifier5000 in addition to, or instead of, a pressure sensor 4272 provided inthe RPT device 4000.

5.6.2.4.2 Flow Rate Transducer

One or more flow rate transducers 5214 may be provided to the humidifier5000 in addition to, or instead of, a flow rate sensor 4274 provided inthe RPT device.

5.6.2.4.3 Temperature Transducer

The humidifier 5000 may comprise one or more temperature transducers5216. The one or more temperature transducers 5216 may be configured tomeasure one or more temperatures such as of the heating element 5240and/or of the flow of air downstream of the humidifier outlet. In someforms, the humidifier 5000 may further comprise a temperature sensor5216 to detect the temperature of the ambient air.

5.6.2.4.4 Humidity Transducer

In one form, the humidifier 5000 may comprise one or more humiditysensors 5218 to detect a humidity of a gas, such as the ambient air. Thehumidity sensor 5218 may be placed towards the humidifier outlet in someforms to measure a humidity of the gas delivered from the humidifier5000. The humidity sensor may be an absolute humidity sensor or arelative humidity sensor.

5.6.2.5 Heating Element

As shown in FIGS. 6B, 20A and other figures, a heater plate 6080 is usedto transfer heat to the water reservoir. In the illustrated example, theheater plate may form a part of the reservoir dock 6050, and may belocated on or near the base of the reservoir dock. At least the toplayer of the heater plate comprises a hard scratch resistant surfacethat may be formed, for example, of a nickel chrome alloy, stainlesssteel or anodised aluminium. The heater plate may transfer heat from aheating element. The heating element may comprise a heat generatingcomponent such as an electrically resistive heating track. One suitableexample of a heating element is a layered heating element such as onedescribed in the PCT Patent Application Publication No. WO 2012/171072,which is incorporated herewith by reference in its entirety.

FIGS. 34A to 34C show a heating assembly 6075 according to an example ofthe present technology. In the illustrated example, the heating assembly6075 includes a heater plate 6080, a heating element 6085, and a thermalpad 6088 (e.g., thermo-conductive rubber or ceramic pad) arrangedbetween the heater plate 6080 and the heating element 6085. The heatingassembly 6075 may further comprise a support structure 6089 structuredand arranged to support the heater plate/thermal pad/heating element atthe bottom of the reservoir dock 6050. In the illustrated example, thesupport structure 6089 includes a peripheral resilient supporting member6096 and a base plate 6097 to support the resilient supporting member6096 at the bottom of the reservoir dock 6050. As illustrated, inaddition to the resilient supporting member 6096 (e.g., constructed ofan elastomeric material (e.g., silicone)), one or more support cones6098 (e.g., see FIGS. 34A and 34C) or tubes (e.g., see FIGS. 103 and104) may also be used to resiliently support the heater plate/thermalpad/heating element.

The thermal pad is preferably made by a pliable or compliantthermo-conductive material and is arranged between the heater plate 6080and the heating element 6085 (e.g., engages or sticks (e.g., bonds) toboth the heater plate and the heating element). In this arrangement, thethermal pad can fill the air gaps or spaces between heater plate 6080and the heating element 6085, which enhances thermal conductivity fromthe heating element 6085 to the heater plate 6080. As both the heaterplate 6080 and the heating element 6085 typically include planarsurfaces made of a hard material, any small imperfections on thesurfaces may cause air gaps between these two surfaces. Having thepliable layer between these surfaces helps with removing such air gapsand improving the thermal conductivity of the system.

FIGS. 81, 98, 100, and 103-109 show a heating assembly 6075 according toanother example of the present technology. In the illustrated example,the heating assembly 6075 (e.g., see FIG. 103) includes a heater plateor wear plate 6080, a heating element or heater 6085, and a thermal pad6088 (e.g., thermo-conductive rubber or ceramic pad) arranged betweenthe heater plate 6080 and the heating element 6085 (see FIG. 103). Theheating assembly 6075 further comprises a support structure 6089structured and arranged to support the heater plate/thermal pad/heatingelement at the bottom of the reservoir dock 6050 (see FIG. 103).

The support structure 6089 includes a resilient sealing and supportingmember 9500 and a base plate 9600 to support the resilient sealing andsupporting member 9500 at the bottom of the reservoir dock 6050 (seeFIG. 104). As described below, the resilient sealing and supportingmember 9500 (e.g., constructed of an elastomeric material (e.g.,silicone)) resiliently suspends the heater plate/thermal pad/heatingelement assembly within the reservoir dock 6050 so that the heater plateis be biased upwardly by the resilient sealing and supporting member9500 against the conductive portion 6150 of the water reservoir 6100when the water reservoir 6100 is inserted in the reservoir dock 6050.The bias keeps the heater plate 6080 and the conductive portion 6150pressed against each other to enhance thermal conductivity between them.

In the illustrated example, the base plate 9600 (e.g., constructed of aplastic or thermoplastic polymer material) comprises a continuousinterior base surface 9610 and a peripheral flange 9620 that extendsupwards and outwards (directions applicable when the integrated RPTdevice and humidifier 6000 are in an operational configuration) from thebase surface 9610. As best shown in FIG. 106, the peripheral flange 9620is configured and arranged to extend up and over a base wall 8005 thatforms an opening at the bottom of the integrated RPT device andhumidifier 6000, and to form a removable or non-removable connection(e.g., via a plurality of connection stakes 9622—see FIG. 104) with aninner wall 6052 (see FIGS. 106, 108, 109) of the reservoir dock 6050. Inthe illustrated example, the exterior base surface 9612 of the baseplate 9600 forms an outer, exterior surface of the integrated RPT deviceand humidifier 6000 (see FIG. 106).

In some examples, the resilient sealing and supporting member 9500 islaid down over a flat base surface 9610. In another example (see FIGS.104 and 106), raised tracks 9615 may be provided to the base surface9610 of the base plate 9600, which tracks 9615 are configured to alignand laterally support at least the one or more resilient hollow tubes9520 of the resilient sealing and supporting member 9500 on the baseplate 9600. The resilient hollow tubes 9520 will be described in moredetail further in the text. In some cases, tracks 9615 are configured toalign and laterally support the entire resilient sealing and supportingmember 9500 on the base plate 9600. Also, as described in more detailbelow, one or more drain holes or cut-outs 9625 (e.g., 9 drain holes asshown in FIG. 104) are provided along the perimeter of the peripheralflange 9620 to allow drainage of water that may collect in the baseplate 9600 during use.

The resilient sealing and supporting member 9500 comprises a resilientperipheral lip 9510 and one or more resilient hollow tubes 9520 (e.g.,hollow cylinders) distributed within the space bounded by the resilientperipheral lip 9510. In the illustrated example, the peripheral lip 9510and the hollow tubes 9520 comprise a one-piece molded construction (ofan elastomeric material (e.g., silicone)), e.g., with one or moreintermediate connectors 9530 to interconnect the peripheral lip 9510 andthe hollow tubes 9520. Also, a wire or cable guide 9540 can be providedto the peripheral lip 9510 to accommodate one or wires or cables thatelectrically connect the heater 6085 to the PCBA 7600.

When provided to the base plate 9600, the peripheral lip 9510 isconfigured to extend on the inner side of the peripheral flange 9620 ina substantially upward (with respect to the operation configuration ofthe device) direction (see FIG. 106), with some possible slight outwardflaring in the upper portion of the flange. In an example, theperipheral lip 9510 may extend concentrically to the peripheral flange9620 (see FIG. 103). Each of the hollow tubes 9520 includes one endsupported by the base surface 9610 and an opposite end configured toengage the heater 6085 when the heating assembly 6075 is assembled tothe reservoir dock 6050 (see FIG. 106). The resilient sealing andsupporting member 9500 may be either removably, or permanentlyattachable to the base surface 9610 of the base plate 9600, e.g., by wayof adhesive, over-molding, etc.

In the illustrated example, each of the hollow tubes 9520 includes anaxis that is generally vertically oriented, i.e., generallyperpendicular to the generally horizontally oriented and planar basesurface 6882 of the base 6880. In the illustrated example, the resilientsealing and supporting member 9500 comprises 4 hollow tubes 9520,however it should be appreciated that more or less hollow tubes may beprovided. In an example, each of the hollow tubes 9520 may include aheight of about 7-8 mm, an internal diameter of about 7 mm, and a wallthickness of about 1 mm, however other suitable dimensions, which maydepend on the number of cylinders used, are also possible.

The heater plate or wear plate 6080 (see FIG. 81) is arranged within anopening provided to a bottom wall 6053 of the reservoir dock 6050, whicharranges the heater plate 6080 within the dock cavity for engagementwith the conductive portion 6150 of the water reservoir 6100 in use. Theheater plate 6080 (e.g., constructed (e.g., stamped) of a metallicmaterial (e.g., stainless steel having uniform wall thickness of about0.15 mm)) comprises a base 6880 and a skirt 6885 extending around theperimeter of the base 6880 (see FIGS. 103 and 106).

The base 6880 includes a first side that forms an exterior or basesurface 6882 adapted to engage the conductive portion 6150 of the waterreservoir 6100 in use. A second side of the base 6880 forms an interiorsurface 6884 engaged with the thermal pad 6088 (see FIG. 106). Asillustrated, the base 6880 comprises a generally planar shape configuredto extend substantially horizontally when the integrated RPT device andhumidifier 6000 is in an operational configuration.

The skirt 6885 may be horizontal (a simple extension of the base 6880),but is preferably sloped or angled generally downwardly and generallyoutwardly with respect to the base 6880. The skirt can, thus, be formedby a single portion extending downwardly and outwardly from the base6880. In the illustrated example, the skirt 6885 includes a verticalportion 6885 v that extends substantially vertically with respect to thebase 6880, which leads to a horizontal portion 6885 h that extends in asubstantially horizontal plane to that of the base 6880 (see FIGS. 103and 106).

When assembled to the reservoir dock 6050 (with the water reservoir 6100removed), the resilient sealing and supporting member 9500 resilientlysupports the heater plate 6080 (along with the heater 6085 and thethermal pad 6088) such that the base 6880 protrudes through the openingin the bottom wall 6053 and the horizontal portion 6885 h of the skirt6885 engages underneath the bottom wall 6053 which provides a hard stopto retain the heater plate 6080 within the opening (see FIG. 106).

More specifically, as best shown in FIG. 106, the heater 6085 and thethermal pad 6088 are arranged within a pocket of the heater plate 6080formed by the base 6880 and the vertical portion 6885 v of the skirt6885. One side of the heater 6085 is engaged with the hollow tubes 9520within the boundaries of the peripheral lip 9510, and the opposite sideof the heater 6085 is engaged with the thermal pad 6088 which engagesthe interior surface 6884 of the base 6880. Instead of all hollow tubes9520 being engaged with the heater 6085, some or all of the supportingmembers (in this case—vertical hollow tubes 9520) may be engageddirectly with the interior surface 6884 of the base 6880. Further, theperipheral lip 9510 of the resilient sealing and supporting member 9500engages underneath the horizontal portion 6885 h of the skirt 6885 ofthe heater plate 6080. As a result of this configuration, the heaterplate 6080 is supported in two ways, i.e., along its periphery (thehorizontal portion 6885 h) by the peripheral lip 9510, and along itscentral base 6880 by the hollow tubes 9520.

In an example, the thermal pad 6088 may include only one side that issticky, e.g., thermal pad 6088 includes an adhesive on one side to stickto the heater 6085 and an opposite side that is not sticky that engagesthe heater plate 6080. A non-sticky thermal pad can also be used, as thehollow tubes 9520 can be designed to apply continuous pressure thatkeeps thermal contact between components within the thermal pad 6088. Asa result, the thermal pad/heater may move within the pocket of theheater plate 6080, however even when moved, the heater plate/thermalpad/heater will remain supported by the hollow tubes 9520. As notedabove, the thermal pad 6088 is configured to fill the air gaps or spacesbetween heater plate 6080 and the heating element 6085, which enhancesthermal conductivity from the heating element 6085 to the heater plate6080.

The resilient sealing and supporting member 9500 provides the heaterplate/thermal pad/heater with a spring-like resistance to any downwardpressure (which is in axial direction for the hollow tubes 9520) appliedby the water reservoir 6100 to the heater plate 6080 when the waterreservoir 6100 is inserted into the reservoir dock 6050. Such aresistance provides a constant upward spring bias to the heater plate6080 that allows a good mechanical and thermal contact between theheater plate 6080 and the conductive portion 6150 of the water reservoir6100 when the water reservoir is in its operating configuration. Suchgood mechanical and thermal contact a more efficient operation of thedevice.

The specific configuration of the vertically oriented hollow tubes 9520supporting the heater plate 6080 ensures a more linear resilientresponse to downward pressure applied to the base 6880 of the heaterplate 6080 by the inserted water reservoir 6100. This compares favorablyto the case of a solid-structured resilient supporting members that, ifdepressed beyond a certain limit, may provide a very strong resistanceto any further deflection of the heater plate 6080. Such strongresistance may cause a high friction and make insertion of a waterreservoir 6100 difficult for the user.

FIGS. 105 and 106 show the heating assembly 6075 when the waterreservoir 6100 is removed from the reservoir dock 6050, and FIGS. 107and 108 show the heating assembly 6075 when the water reservoir 6100 isinserted into the reservoir dock 6050. As illustrated, when the waterreservoir 6100 is inserted into the reservoir dock 6050, the resilientsealing and supporting member 9500 is so configured that, whendepressed, it resiliently deflects (e.g., the peripheral lip 9510 curlsalong its length and the side wall of each hollow tube 9520 bucklesradially outwardly), which resilient deflection provides the upwardbiasing force to bias the heater plate 6080 upwardly against theconductive portion 6150 of the water reservoir 6100. The biasing forcebiases the heater plate 6080 (via thermal pad 6088) to the conductiveportion 6150 of the water reservoir 6100. This leads to an improvedmechanical and thermal contact between the heater plate 6080 and theconductive portion 6150, thus enhancing the overall humidificationperformance. As mentioned earlier in the text, the mechanics of thevertically oriented flexible hollow tube 9520 buckling under pressure(applied by the inserted water reservoir) ensures a more linearresilient response, which may provide for a relatively smooth insertionof the water reservoir into the water reservoir dock. This is especiallyuseful when a water reservoir with a vertical dimension at the upper endof the dimensional tolerance, is inserted in the dock. Even though anincreased pressure is applied vertically on the resilient member in thiscase, because the heater plate 6080 is deflected further down by theslightly larger vertical dimension of the tub, the relatively linearresponse of the buckled tubes may ensure a relatively minor increase inthe resistance to the insertion of the tub.

In an example, the normal displacement of the heater plate 6080 causedby the insertion of the water reservoir 6100 is about 1-2 mm (i.e. howmuch the heater plate 6080 is pushed down from its rest or stoppedposition in FIGS. 105-106 when the water reservoir 6100 is inserted).Displacement is at least greater than 0 mm to ensure interference of theheater plate 6080 with the conductive portion 6150 of the waterreservoir 6100. In an example, the resilient sealing and supportingmember 9500 may include a nominal pre-load when the water reservoir 6100is removed from the reservoir dock 6050. In an example, the pre-loadand/or the displacement may be adjusted by the edge height or thicknessof the bottom wall 6053 of the dock 6050 which provides a stop or end oftravel for the heater plate 6080.

In an example, as shown in FIG. 104, in one or more of the tubes, thetop edge (adjacent the heater 6085) of each of the hollow tubes 9520 mayinclude one or more edge cut-outs 9550 which form air-bleed apertures toallow the release of air (from the interior of each hollow tube) wheneach of the hollow tubes 9520 are depressed or deflected when the waterreservoir 6100 is inserted into the reservoir dock 6050. In analternative example, the wall of one or more of the hollow tubes 9520may include one or more holes to provide air-bleed aperture(s) for therelease of air when the tubes are under pressure. The function of theedge cut-out/s or opening/s in the tube wall is to ensure anequalisation of pressure to maintain a consistent spring force function.During a depression of the heater plate, for example during insertion ofthe water reservoir, the volume within the vertical tube/s will becompressed, forcing air to move outside the cylindrical shape. Thiscreates a risk of a vacuum being formed inside any one hollow tube.Since each tube essentially acts as a spring, the formation of vacuum ina tube may change the reaction force applied by the tube to the heater,and therefore, to the heated base of the humidification reservoir. Theformation of (potentially) different degrees of vacuum in one or moretubes (springs), can cause various response pressure to be applied todifferent points across the surface of the heater. This can potentiallycause various degrees of thermal contact between the heater and thewater reservoir base, across the area of the heater/base, which mayresult in a reduction in humidification performance. The inclusion ofcut-outs or openings in the side wall of the cylinders can minimise thevariation in the hollow tubes spring force, resulting in betterhumidification performance.

As shown in FIG. 109, the heater plate 6080 and the resilient sealingand supporting member 9500 are arranged so that any water spilled insidethe cavity of the reservoir dock 6050 is sealed out of the peripherallip 9510 and prevented from reaching the space on the inner side of theperipheral lip 9510, where the heater 6085 is located. Moreover, thespilled water may leak through the drain holes 9625 (see FIG. 104) alongthe perimeter of the base plate 9600 and be released onto an underlyingsupporting surface (e.g., bedside table).

That is, with reference to FIGS. 107 to 109, the peripheral lip 9510resiliently engages underneath the horizontal portion 6885 h of theskirt 6885 and forms a seal along the perimeter of the heater plate6080. When water from the heater reservoir 6100 spills inside the cavityof the reservoir dock 6050, it will pass through the small gap 6890between the heater plate 6080 and the bottom wall 6053 of the dock 6050and into a reservoir 6891 formed between the peripheral lip 9510 and theperipheral flange 9620 of the base plate 9600 (see FIG. 109). Suchtrapped water in the reservoir 6891 can then flow through the drainholes 9625 along the perimeter of the peripheral flange 9620, andthrough the small gap 6892 between the base wall 8005 and the base plate9600, to allow drainage onto the underlying supporting surface (see FIG.109).

It should be noted that any references in the above description tohorizontal, vertical, downward and upward directions are meant to applywith respect to an operational configuration of the integrated RPTdevice and humidifier 6000.

5.6.2.6 Humidifier Controller

According to one arrangement of the present technology, a humidifier5000 may comprise a humidifier controller 5250 as shown in FIG. 5G. Inone form, the humidifier controller 5250 may be a part of the centralcontroller 4230. In another form, the humidifier controller 5250 may bea separate controller, which may be in communication with the centralcontroller 4230.

In one form, the humidifier controller 5250 may receive as inputsmeasures of properties (such as temperature, humidity, pressure and/orflow rate), for example of the flow of air, the water in the reservoir5110 and/or the humidifier 5000. The humidifier controller 5250 may alsobe configured to execute or implement humidifier algorithms and/ordeliver one or more output signals.

As shown in FIG. 5G, the humidifier controller 5250 may comprise one ormore controllers, such as a central humidifier controller 5251, a heatedair circuit controller 5254 configured to control the temperature of aheated air circuit 4171 and/or a heating element controller 5252configured to control the temperature of a heating element 5240.

5.7 Breathing Waveforms

FIG. 4 shows a model typical breath waveform of a person while sleeping.The horizontal axis is time, and the vertical axis is respiratory flowrate. While the parameter values may vary, a typical breath may have thefollowing approximate values: tidal volume Vt 0.5 L, inhalation time Ti1.6 s, peak inspiratory flow rate Qpeak 0.4 L/s, exhalation time Te 2.4s, peak expiratory flow rate Qpeak −0.5 L/s. The total duration of thebreath, Ttot, is about 4 s. The person typically breathes at a rate ofabout 15 breaths per minute (BPM), with Ventilation Vent about 7.5L/min. A typical duty cycle, the ratio of Ti to Ttot, is about 40%.

5.8 Glossary

For the purposes of the present technology disclosure, in certain formsof the present technology, one or more of the following definitions mayapply. In other forms of the present technology, alternative definitionsmay apply.

5.8.1 General

Air: In certain forms of the present technology, air may be taken tomean atmospheric air, and in other forms of the present technology airmay be taken to mean some other combination of breathable gases, e.g.atmospheric air enriched with oxygen.

Ambient: In certain forms of the present technology, the term ambientwill be taken to mean (i) external of the treatment system or patient,and (ii) immediately surrounding the treatment system or patient.

For example, ambient humidity with respect to a humidifier may be thehumidity of air immediately surrounding the humidifier, e.g. thehumidity in the room where a patient is sleeping. Such ambient humiditymay be different to the humidity outside the room where a patient issleeping.

In another example, ambient pressure may be the pressure immediatelysurrounding or external to the body.

In certain forms, ambient (e.g., acoustic) noise may be considered to bethe background noise level in the room where a patient is located, otherthan for example, noise generated by an RPT device or emanating from amask or patient interface. Ambient noise may be generated by sourcesoutside the room.

Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in whichthe treatment pressure is automatically adjustable, e.g. from breath tobreath, between minimum and maximum limits, depending on the presence orabsence of indications of SDB events.

Continuous Positive Airway Pressure (CPAP) therapy: Respiratory pressuretherapy in which the treatment pressure is approximately constantthrough a respiratory cycle of a patient. In some forms, the pressure atthe entrance to the airways will be slightly higher during exhalation,and slightly lower during inhalation. In some forms, the pressure willvary between different respiratory cycles of the patient, for example,being increased in response to detection of indications of partial upperairway obstruction, and decreased in the absence of indications ofpartial upper airway obstruction.

Flow rate: The volume (or mass) of air delivered per unit time. Flowrate may refer to an instantaneous quantity. In some cases, a referenceto flow rate will be a reference to a scalar quantity, namely a quantityhaving magnitude only. In other cases, a reference to flow rate will bea reference to a vector quantity, namely a quantity having bothmagnitude and direction. Flow rate may be given the symbol Q. ‘Flowrate’ is sometimes shortened to simply ‘flow’ or ‘airflow’.

In the example of patient respiration, a flow rate may be nominallypositive for the inspiratory portion of a breathing cycle of a patient,and hence negative for the expiratory portion of the breathing cycle ofa patient. Total flow rate, Qt, is the flow rate of air leaving the RPTdevice. Vent flow rate, Qv, is the flow rate of air leaving a vent toallow washout of exhaled gases. Leak flow rate, Ql, is the flow rate ofleak from a patient interface system or elsewhere. Respiratory flowrate, Qr, is the flow rate of air that is received into the patient'srespiratory system.

Humidifier: The word humidifier will be taken to mean a humidifyingapparatus constructed and arranged, or configured with a physicalstructure to be capable of providing a therapeutically beneficial amountof water (H₂O) vapour to a flow of air to ameliorate a medicalrespiratory condition of a patient.

Leak: The word leak will be taken to be an unintended flow of air. Inone example, leak may occur as the result of an incomplete seal betweena mask and a patient's face. In another example leak may occur in aswivel elbow to the ambient.

Noise, conducted (acoustic): Conducted noise in the present documentrefers to noise which is carried to the patient by the pneumatic path,such as the air circuit and the patient interface as well as the airtherein. In one form, conducted noise may be quantified by measuringsound pressure levels at the end of an air circuit.

Noise, radiated (acoustic): Radiated noise in the present documentrefers to noise which is carried to the patient by the ambient air. Inone form, radiated noise may be quantified by measuring soundpower/pressure levels of the object in question according to ISO 3744.

Noise, vent (acoustic): Vent noise in the present document refers tonoise which is generated by the flow of air through any vents such asvent holes of the patient interface.

Patient: A person, whether or not they are suffering from a respiratorycondition.

Pressure: Force per unit area. Pressure may be expressed in a range ofunits, including cmH₂O, g-f/cm² and hectopascal. 1 cmH₂O is equal to 1g-f/cm² and is approximately 0.98 hectopascal. In this specification,unless otherwise stated, pressure is given in units of cmH₂O.

The pressure in the patient interface is given the symbol Pm, while thetreatment pressure, which represents a target value to be achieved bythe mask pressure Pm at the current instant of time, is given the symbolPt.

Respiratory Pressure Therapy (RPT): The application of a supply of airto an entrance to the airways at a treatment pressure that is typicallypositive with respect to atmosphere.

Ventilator: A mechanical device that provides pressure support to apatient to perform some or all of the work of breathing.

5.8.1.1 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression moulded silicone rubber (CMSR). One formof commercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, an exemplary form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240.

Polycarbonate: a thermoplastic polymer of Bisphenol-A Carbonate.

5.8.1.2 Mechanical Properties

Resilience: Ability of a material to absorb energy when deformedelastically and to release the energy upon unloading.

Resilient: Will release substantially all of the energy when unloaded.Includes e.g. certain silicones, and thermoplastic elastomers.

Hardness: The ability of a material per se to resist deformation (e.g.described by a Young's Modulus, or an indentation hardness scalemeasured on a standardised sample size).

-   -   ‘Soft’ materials may include silicone or thermo-plastic        elastomer (TPE), and may, e.g. readily deform under finger        pressure.    -   ‘Hard’ materials may include polycarbonate, polypropylene, steel        or aluminium, and may not e.g. readily deform under finger        pressure.

Stiffness (or rigidity) of a structure or component: The ability of thestructure or component to resist deformation in response to an appliedload. The load may be a force or a moment, e.g. compression, tension,bending or torsion. The structure or component may offer differentresistances in different directions.

Floppy structure or component: A structure or component that will changeshape, e.g. bend, when caused to support its own weight, within arelatively short period of time such as 1 second.

Rigid structure or component: A structure or component that will notsubstantially change shape when subject to the loads typicallyencountered in use. An example of such a use may be setting up andmaintaining a patient interface in sealing relationship with an entranceto a patient's airways, e.g. at a load of approximately 20 to 30 cmH₂Opressure.

As an example, an I-beam may comprise a different bending stiffness(resistance to a bending load) in a first direction in comparison to asecond, orthogonal direction. In another example, a structure orcomponent may be floppy in a first direction and rigid in a seconddirection.

5.8.2 Respiratory Cycle

Apnea: According to some definitions, an apnea is said to have occurredwhen flow falls below a predetermined threshold for a duration, e.g. 10seconds. An obstructive apnea will be said to have occurred when,despite patient effort, some obstruction of the airway does not allowair to flow. A central apnea will be said to have occurred when an apneais detected that is due to a reduction in breathing effort, or theabsence of breathing effort, despite the airway being patent. A mixedapnea occurs when a reduction or absence of breathing effort coincideswith an obstructed airway.

Breathing rate: The rate of spontaneous respiration of a patient,usually measured in breaths per minute.

Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.

Effort (breathing): The work done by a spontaneously breathing personattempting to breathe.

Expiratory portion of a breathing cycle: The period from the start ofexpiratory flow to the start of inspiratory flow.

Flow limitation: Flow limitation will be taken to be the state ofaffairs in a patient's respiration where an increase in effort by thepatient does not give rise to a corresponding increase in flow. Whereflow limitation occurs during an inspiratory portion of the breathingcycle it may be described as inspiratory flow limitation. Where flowlimitation occurs during an expiratory portion of the breathing cycle itmay be described as expiratory flow limitation.

Types of flow limited inspiratory waveforms:

(i) Flattened: Having a rise followed by a relatively flat portion,followed by a fall.

(ii) M-shaped: Having two local peaks, one at the leading edge, and oneat the trailing edge, and a relatively flat portion between the twopeaks.

(iii) Chair-shaped: Having a single local peak, the peak being at theleading edge, followed by a relatively flat portion.

(iv) Reverse-chair shaped: Having a relatively flat portion followed bysingle local peak, the peak being at the trailing edge.

Hypopnea: According to some definitions, a hypopnea is taken to be areduction in flow, but not a cessation of flow. In one form, a hypopneamay be said to have occurred when there is a reduction in flow below athreshold rate for a duration. A central hypopnea will be said to haveoccurred when a hypopnea is detected that is due to a reduction inbreathing effort. In one form in adults, either of the following may beregarded as being hypopneas:

(i) a 30% reduction in patient breathing for at least 10 seconds plus anassociated 4% desaturation; or(ii) a reduction in patient breathing (but less than 50%) for at least10 seconds, with an associated desaturation of at least 3% or anarousal.

Hyperpnea: An increase in flow to a level higher than normal.

Inspiratory portion of a breathing cycle: The period from the start ofinspiratory flow to the start of expiratory flow will be taken to be theinspiratory portion of a breathing cycle.

Patency (airway): The degree of the airway being open, or the extent towhich the airway is open. A patent airway is open. Airway patency may bequantified, for example with a value of one (1) being patent, and avalue of zero (0), being closed (obstructed).

Positive End-Expiratory Pressure (PEEP): The pressure above atmospherein the lungs that exists at the end of expiration.

Peak flow rate (Qpeak): The maximum value of flow rate during theinspiratory portion of the respiratory flow waveform.

Respiratory flow rate, patient airflow rate, respiratory airflow rate(Qr): These terms may be understood to refer to the RPT device'sestimate of respiratory flow rate, as opposed to “true respiratory flowrate” or “true respiratory flow rate”, which is the actual respiratoryflow rate experienced by the patient, usually expressed in litres perminute.

Tidal volume (Vt): The volume of air inhaled or exhaled during normalbreathing, when extra effort is not applied. In principle theinspiratory volume Vi (the volume of air inhaled) is equal to theexpiratory volume Ve (the volume of air exhaled), and therefore a singletidal volume Vt may be defined as equal to either quantity. In practicethe tidal volume Vt is estimated as some combination, e.g. the mean, ofthe inspiratory volume Vi and the expiratory volume Ve.

(inhalation) Time (Ti): The duration of the inspiratory portion of therespiratory flow rate waveform.

(exhalation) Time (Te): The duration of the expiratory portion of therespiratory flow rate waveform.

(total) Time (Ttot): The total duration between the start of oneinspiratory portion of a respiratory flow rate waveform and the start ofthe following inspiratory portion of the respiratory flow rate waveform.

Typical recent ventilation: The value of ventilation around which recentvalues of ventilation Vent over some predetermined timescale tend tocluster, that is, a measure of the central tendency of the recent valuesof ventilation.

Upper airway obstruction (UAO): includes both partial and total upperairway obstruction. This may be associated with a state of flowlimitation, in which the flow rate increases only slightly or may evendecrease as the pressure difference across the upper airway increases(Starling resistor behaviour).

Ventilation (Vent): A measure of a rate of gas being exchanged by thepatient's respiratory system. Measures of ventilation may include one orboth of inspiratory and expiratory flow, per unit time. When expressedas a volume per minute, this quantity is often referred to as “minuteventilation”. Minute ventilation is sometimes given simply as a volume,understood to be the volume per minute.

5.8.3 Ventilation

Adaptive Servo-Ventilator (ASV): A servo-ventilator that has achangeable, rather than fixed target ventilation. The changeable targetventilation may be learned from some characteristic of the patient, forexample, a respiratory characteristic of the patient.

Backup rate: A parameter of a ventilator that establishes the minimumbreathing rate (typically in number of breaths per minute) that theventilator will deliver to the patient, if not triggered by spontaneousrespiratory effort.

Cycled: The termination of a ventilator's inspiratory phase. When aventilator delivers a breath to a spontaneously breathing patient, atthe end of the inspiratory portion of the breathing cycle, theventilator is said to be cycled to stop delivering the breath.

Expiratory positive airway pressure (EPAP): a base pressure, to which apressure varying within the breath is added to produce the desired maskpressure which the ventilator will attempt to achieve at a given time.

End expiratory pressure (EEP): Desired mask pressure which theventilator will attempt to achieve at the end of the expiratory portionof the breath. If the pressure waveform template Π(Φ) is zero-valued atthe end of expiration, i.e. Π(Φ)=0 when Φ=1, the EEP is equal to theEPAP.

Inspiratory positive airway pressure (IPAP): Maximum desired maskpressure which the ventilator will attempt to achieve during theinspiratory portion of the breath.

Pressure support: A number that is indicative of the increase inpressure during ventilator inspiration over that during ventilatorexpiration, and generally means the difference in pressure between themaximum value during inspiration and the base pressure (e.g.,PS=IPAP−EPAP). In some contexts pressure support means the differencewhich the ventilator aims to achieve, rather than what it actuallyachieves.

Servo-ventilator: A ventilator that measures patient ventilation, has atarget ventilation, and which adjusts the level of pressure support tobring the patient ventilation towards the target ventilation.

Spontaneous/Timed (S/T): A mode of a ventilator or other device thatattempts to detect the initiation of a breath of a spontaneouslybreathing patient. If however, the device is unable to detect a breathwithin a predetermined period of time, the device will automaticallyinitiate delivery of the breath.

Swing: Equivalent term to pressure support.

Triggered: When a ventilator delivers a breath of air to a spontaneouslybreathing patient, it is said to be triggered to do so at the initiationof the respiratory portion of the breathing cycle by the patient'sefforts.

5.8.4 Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: An elbow is an example of a structure that directs an axis offlow of air travelling therethrough to change direction through anangle. In one form, the angle may be approximately 90 degrees. Inanother form, the angle may be more, or less than 90 degrees. The elbowmay have an approximately circular cross-section. In another form theelbow may have an oval or a rectangular cross-section. In certain formsan elbow may be rotatable with respect to a mating component, e.g. about360 degrees. In certain forms an elbow may be removable from a matingcomponent, e.g. via a snap connection. In certain forms, an elbow may beassembled to a mating component via a one-time snap during manufacture,but not removable by a patient.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. For example theheadgear may comprise a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to mean a portion ofa patient interface having walls at least partially enclosing a volumeof space, the volume having air therein pressurised above atmosphericpressure in use. A shell may form part of the walls of a mask plenumchamber.

Seal: May be a noun form (“a seal”) which refers to a structure, or averb form (“to seal”) which refers to the effect. Two elements may beconstructed and/or arranged to ‘seal’ or to effect ‘sealing’therebetween without requiring a separate ‘seal’ element per se.

Shell: A shell will be taken to mean a curved, relatively thin structurehaving bending, tensile and compressive stiffness. For example, a curvedstructural wall of a mask may be a shell. In some forms, a shell may befaceted. In some forms a shell may be airtight. In some forms a shellmay not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel (noun): A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. There may be little orno leak flow of air from the swivel in use.

Tie (noun): A structure designed to resist tension.

Vent: (noun): A structure that allows a flow of air from an interior ofthe mask, or conduit, to ambient air for clinically effective washout ofexhaled gases. For example, a clinically effective washout may involve aflow rate of about 10 litres per minute to about 100 litres per minute,depending on the mask design and treatment pressure.

5.8.5 Shape of Structures

Products in accordance with the present technology may comprise one ormore three-dimensional mechanical structures, for example a mask cushionor an impeller. The three-dimensional structures may be bounded bytwo-dimensional surfaces. These surfaces may be distinguished using alabel to describe an associated surface orientation, location, function,or some other characteristic. For example a structure may comprise oneor more of an anterior surface, a posterior surface, an interior surfaceand an exterior surface. In another example, a seal-forming structuremay comprise a face-contacting (e.g. outer) surface, and a separatenon-face-contacting (e.g. underside or inner) surface. In anotherexample, a structure may comprise a first surface and a second surface.

To facilitate describing the shape of the three-dimensional structuresand the surfaces, we first consider a cross-section through a surface ofthe structure at a point, p. See FIG. 3B to FIG. 3F, which illustrateexamples of cross-sections at point p on a surface, and the resultingplane curves. FIGS. 3B to 3F also illustrate an outward normal vector atp. The outward normal vector at p points away from the surface. In someexamples we describe the surface from the point of view of an imaginarysmall person standing upright on the surface.

5.8.5.1 Curvature in One Dimension

The curvature of a plane curve at p may be described as having a sign(e.g. positive, negative) and a magnitude (e.g. 1/radius of a circlethat just touches the curve at p).

Positive curvature: If the curve at p turns towards the outward normal,the curvature at that point will be taken to be positive (if theimaginary small person leaves the point p they must walk uphill). SeeFIG. 3B (relatively large positive curvature compared to FIG. 3C) andFIG. 3C (relatively small positive curvature compared to FIG. 3B). Suchcurves are often referred to as concave.

Zero curvature: If the curve at p is a straight line, the curvature willbe taken to be zero (if the imaginary small person leaves the point p,they can walk on a level, neither up nor down). See FIG. 3D.

Negative curvature: If the curve at p turns away from the outwardnormal, the curvature in that direction at that point will be taken tobe negative (if the imaginary small person leaves the point p they mustwalk downhill). See FIG. 3E (relatively small negative curvaturecompared to FIG. 3F) and FIG. 3F (relatively large negative curvaturecompared to FIG. 3E). Such curves are often referred to as convex.

5.8.5.2 Curvature of Two Dimensional Surfaces

A description of the shape at a given point on a two-dimensional surfacein accordance with the present technology may include multiple normalcross-sections. The multiple cross-sections may cut the surface in aplane that includes the outward normal (a “normal plane”), and eachcross-section may be taken in a different direction. Each cross-sectionresults in a plane curve with a corresponding curvature. The differentcurvatures at that point may have the same sign, or a different sign.Each of the curvatures at that point has a magnitude, e.g. relativelysmall. The plane curves in FIGS. 3B to 3F could be examples of suchmultiple cross-sections at a particular point.

Principal curvatures and directions: The directions of the normal planeswhere the curvature of the curve takes its maximum and minimum valuesare called the principal directions. In the examples of FIG. 3B to FIG.3F, the maximum curvature occurs in FIG. 3B, and the minimum occurs inFIG. 3F, hence FIG. 3B and FIG. 3F are cross sections in the principaldirections. The principal curvatures at p are the curvatures in theprincipal directions.

Region of a surface: A connected set of points on a surface. The set ofpoints in a region may have similar characteristics, e.g. curvatures orsigns.

Saddle region: A region where at each point, the principal curvatureshave opposite signs, that is, one is positive, and the other is negative(depending on the direction to which the imaginary person turns, theymay walk uphill or downhill).

Dome region: A region where at each point the principal curvatures havethe same sign, e.g. both positive (a “concave dome”) or both negative (a“convex dome”).

Cylindrical region: A region where one principal curvature is zero (or,for example, zero within manufacturing tolerances) and the otherprincipal curvature is non-zero.

Planar region: A region of a surface where both of the principalcurvatures are zero (or, for example, zero within manufacturingtolerances).

Edge of a surface: A boundary or limit of a surface or region.

Path: In certain forms of the present technology, ‘path’ will be takento mean a path in the mathematical—topological sense, e.g. a continuousspace curve from f(0) to f(1) on a surface. In certain forms of thepresent technology, a ‘path’ may be described as a route or course,including e.g. a set of points on a surface. (The path for the imaginaryperson is where they walk on the surface, and is analogous to a gardenpath).

Path length: In certain forms of the present technology, ‘path length’will be taken to mean the distance along the surface from f(0) to f(1),that is, the distance along the path on the surface. There may be morethan one path between two points on a surface and such paths may havedifferent path lengths. (The path length for the imaginary person wouldbe the distance they have to walk on the surface along the path).

Straight-line distance: The straight-line distance is the distancebetween two points on a surface, but without regard to the surface. Onplanar regions, there would be a path on the surface having the samepath length as the straight-line distance between two points on thesurface. On non-planar surfaces, there may be no paths having the samepath length as the straight-line distance between two points. (For theimaginary person, the straight-line distance would correspond to thedistance ‘as the crow flies’.)

5.8.5.3 Space Curves

Space curves: Unlike a plane curve, a space curve does not necessarilylie in any particular plane. A space curve may be closed, that is,having no endpoints. A space curve may be considered to be aone-dimensional piece of three-dimensional space. An imaginary personwalking on a strand of the DNA helix walks along a space curve. Atypical human left ear comprises a helix, which is a left-hand helix. Atypical human right ear comprises a helix, which is a right-hand helix.The edge of a structure, e.g. the edge of a membrane or impeller, mayfollow a space curve. In general, a space curve may be described by acurvature and a torsion at each point on the space curve. Torsion is ameasure of how the curve turns out of a plane. Torsion has a sign and amagnitude. The torsion at a point on a space curve may be characterisedwith reference to the tangent, normal and binormal vectors at thatpoint.

Tangent unit vector (or unit tangent vector): For each point on a curve,a vector at the point specifies a direction from that point, as well asa magnitude. A tangent unit vector is a unit vector pointing in the samedirection as the curve at that point. If an imaginary person were flyingalong the curve and fell off her vehicle at a particular point, thedirection of the tangent vector is the direction she would betravelling.

Unit normal vector: As the imaginary person moves along the curve, thistangent vector itself changes. The unit vector pointing in the samedirection that the tangent vector is changing is called the unitprincipal normal vector. It is perpendicular to the tangent vector.

Binormal unit vector: The binormal unit vector is perpendicular to boththe tangent vector and the principal normal vector. Its direction may bedetermined by a right-hand rule, or alternatively by a left-hand rule.

Osculating plane: The plane containing the unit tangent vector and theunit principal normal vector.

Torsion of a space curve: The torsion at a point of a space curve is themagnitude of the rate of change of the binormal unit vector at thatpoint. It measures how much the curve deviates from the osculatingplane. A space curve which lies in a plane has zero torsion. A spacecurve which deviates a relatively small amount from the osculating planewill have a relatively small magnitude of torsion (e.g. a gently slopinghelical path). A space curve which deviates a relatively large amountfrom the osculating plane will have a relatively large magnitude oftorsion (e.g. a steeply sloping helical path).

With reference to the right-hand rule, a space curve turning towards thedirection of the right-hand binormal may be considered as having aright-hand positive torsion. A space curve turning away from thedirection of the right-hand binormal may be considered as having aright-hand negative torsion (e.g. a left-hand helix).

Equivalently, and with reference to a left-hand rule, a space curveturning towards the direction of the left-hand binormal may beconsidered as having a left-hand positive torsion (e.g. a left-handhelix). Hence left-hand positive is equivalent to right-hand negative.

5.8.5.4 Holes

A surface may have a one-dimensional hole, e.g. a hole bounded by aplane curve or by a space curve. Thin structures (e.g. a membrane) witha hole, may be described as having a one-dimensional hole. See forexample the one dimensional hole in the surface of structure shown inFIG. 3G, bounded by a plane curve.

A structure may have a two-dimensional hole, e.g. a hole bounded by asurface. For example, an inflatable tyre has a two dimensional holebounded by the interior surface of the tyre. In another example, abladder with a cavity for air or gel could have a two-dimensional hole.In a yet another example, a conduit may comprise a one-dimension hole(e.g. at its entrance or at its exit), and a two-dimension hole boundedby the inside surface of the conduit. See also the two dimensional holethrough the structure shown in FIG. 3I, bounded by a surface as shown.

5.9 Other Remarks

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this technology belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present technology, a limitednumber of the exemplary methods and materials are described herein.

When a particular material is identified as being used to construct acomponent, obvious alternative materials with similar properties may beused as a substitute. Furthermore, unless specified to the contrary, anyand all components herein described are understood to be capable ofbeing manufactured and, as such, may be manufactured together orseparately.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

All publications mentioned herein are incorporated herein by referencein their entirety to disclose and describe the methods and/or materialswhich are the subject of those publications. The publications discussedherein are provided solely for their disclosure prior to the filing dateof the present application. Nothing herein is to be construed as anadmission that the present technology is not entitled to antedate suchpublication by virtue of prior invention. Further, the dates ofpublication provided may be different from the actual publication dates,which may need to be independently confirmed.

The terms “comprises” and “comprising” should be interpreted asreferring to elements, components, or steps in a non-exclusive manner,indicating that the referenced elements, components, or steps may bepresent, or utilized, or combined with other elements, components, orsteps that are not expressly referenced.

The subject headings used in the detailed description are included onlyfor the ease of reference of the reader and should not be used to limitthe subject matter found throughout the disclosure or the claims. Thesubject headings should not be used in construing the scope of theclaims or the claim limitations.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

5.10 REFERENCE SIGNS LIST Feature Item Number patient 1000 bed partner1100 patient interface 3000 seal-forming structure 3100 plenum chamber3200 positioning and stabilizing structure 3300 vent 3400 connectionport 3600 forehead support 3700 RPT device 4000 main panel 4010 frontpanel 4012 side panel 4014 chassis 4016 pneumatic block 4020 air filter4110 inlet air filter 4112 outlet air filter 4114 mufflers 4120 inletmuffler 4122 outlet muffler 4124 pressure generator 4140 blower 4142motor 4144 anti-spill back valve 4160 air circuit 4170 air circuit 4171supplemental oxygen 4180 electrical components 4200 PCBA 4202 powersupply 4210 input device 4220 central controller 4230 clock 4232 therapydevice controller 4240 protection circuits 4250 memory 4260 transducer4270 pressure sensor 4272 flow rate sensor 4274 motor speed transducer4276 data communication interface 4280 remote external communicationnetwork 4282 local external communication network 4284 remote externaldevice 4286 local external device 4288 output device 4290 display driver4292 display 4294 algorithms 4300 pre-processing module 4310 pressurecompensation algorithm 4312 vent flow rate estimation algorithm 4314leak flow rate estimation algorithm 4316 respiratory flow rateestimation algorithm 4318 therapy engine module 4320 phase determinationalgorithm 4321 waveform determination algorithm 4322 ventilationdetermination algorithm 4323 inspiratory flow limitation determinationalgorithm 4324 apnea/hypopnea determination algorithm 4325 snoredetermination algorithm 4326 airway patency determination algorithm 4327target ventilation determination algorithm 4328 therapy control module4330 method 4340 tube portion 4500 dock connector 4600 pinch arms 4610retaining protrusion 4615 lip 4620 contact surface 4625 supportprotrusion 4630 base portion 4640 base 4640bs overmold 46400v protrusion4642 bumps 4644 lip seal 4645 stop surface 4647 internal rib 4648contact assembly 4650 contacts 4655 locking and contact assembly 4660contact assembly 4661 support arm 4662 support portion 4665 contactassembly 4666 contacts 4667 electrical connector 4668 base assembly 4680base 4682 cover 4684 overmold 4690 patient interface connector 4700humidifier 5000 humidifier reservoir 5110 humidifier transducer 5210pressure transducer 5212 flow rate transducer 5214 temperaturetransducer 5216 humidity sensor 5218 heating element 5240 humidifiercontroller 5250 central humidifier controller 5251 heating elementcontroller 5252 air circuit controller 5254 integrated RPT device andhumidifier 6000 reservoir dock 6050 locking recess 6051 inner wall 6052bottom wall 6053 slot 6055 guide slots 6060 heating assembly 6075 heaterplate 6080 heating element 6085 gasket 6086 thermal pad 6088 supportstructure 6089 dock outlet 6090 opening 6091 retainer plate 6095supporting member 6096 base plate 6097 support cone 6098 water reservoir6100 reservoir base 6112 reservoir lid 6114 retention protrusion 6115seal 6116 inlet tube 6120 inlet seal 6122 inlet portion 6123 inlet end6124 outlet portion 6125 outlet end 6126 outlet tube 6130 outlet seal6132 thumb grip 6133 outlet end 6134 inlet end 6136 main body 6140 sidewalls 6142 bottom wall 6144 conductive portion 6150 guide rails 6200guide pins 6250 recess 6260 rails 6262 locking tab 6264 latch 6300 latch6400 locking lever 6402 protrusion 6403 lid connector 6404 slotted end6405 support members 6406 finger tab 6407 locking arrangement 6600button portion 6605 locking arms 6610 locking tabs 6615 intermediatecomponent 6700 tubular portion 6705 inlet end 6710 flange 6712 contactsurface 6715 outlet end 6720 port 6730 port seal 6735 spring arms 6740barbed end 6745 protrusion 6750 guide slot 6755 guide rail 6760 flange6770 cut-outs 6772 channel 6780 contact assembly 6800 contacts 6805contacts 6810 support member 6815 support protrusions 6850 base 6880base surface 6882 interior surface 6884 skirt 6885 vertical portion6885v horizontal portion 6885h gap 6890 reservoir 6891 gap 6892 lockingand contact assembly 6900 base 6910 rear wall 6912 opening 6915 sidewall 6920 recess 6922 recess 6924 recess 6926 retaining wall 6930 stopwall 6935 recess 6940 contact assembly 6950 support member 6952 contacts6955 spring arm 6956 electrical connector 6958 contact support structure6960 cover 6970 drop down section 6060D horizontal section 6060Hhorizontal section 6060H2 thin film conductive portion 6150F metalconductive portion 6150M thin film plate 6152F metal plate 6152M thinfilm side wall 6154F metal side wall 6154M thin film interfacing portion6156F metal interfacing portion 6156M reservoir base with thin film6112F1 reservoir base with thin film 6112F2 reservoir base with metal6112M1 reservoir base with metal 6112M2 reservoir base with metal 6112M3reservoir base with metal/thin film 6112MF1 reservoir base withmetal/thin film 6112MF2 reservoir base with metal thin film 6112MF3metal/thin film conductive portion 6150MF pneumatic block 7100 chassisassembly 7300 chassis inlet 7310 chassis outlet 7320 front ledge 7350guide surface 7355 rear ledge 7360 chassis opening 7380 PCBA 7600external housing 8002 base wall 8005 adaptor 8020 first circuit element8022 second circuit element 8024 shroud 8050 resistor 9010 resistor 9012resistor 9020 resistor 9022 sensor 9030 hinge arm 9100 hinge pin 9105cylindrical surface 9105c flat surface 9105f stop member 9110 clip 9120slot 9122 tab 9125 slot 9200 cylindrical surface 9200c open side 9200oside wall 9210 latch 9220 upwardly oriented surface 9300 tab 9315 tab9320 upwardly oriented surface 9325 downwardly oriented surface 9400abutment edge 9450 sealing and supporting member 9500 peripheral lip9510 hollow tube 9520 intermediate connector 9530 wire guide 9540 airbleed indentation 9550 base plate 9600 interior base surface 9610exterior base surface 9612 tracks 9615 peripheral flange 9620 stakes9622 drain hole 9625 intermediate component 9700 tubular portion 9705inlet end 9710 inlet seal 9715 outlet end 9720 port 9730 port seal 9735pinch arm 9740 barbed end 9745 cross-bar 9750 bumper 9751 bumper 9752bumper 9753 guide slot 9755 surface 9758 guide rail 9760 guide rib 9761flange 9770 bumper 9775 channel 9780 side wall 9790 hole 9792 tab 9795fastener 9799 contact assembly 9950 support member 9952 contacts 9955spring arm 9956 socket 9980

1.-41. (canceled)
 42. A medical treatment apparatus for providing asupply of pressurized breathable air to a patient in a positive pressurerange suitable for treatment of a respiratory disorder, the medicaltreatment apparatus comprising: a flow generator configured topressurize the supply of pressurized breathable air in the positivepressure range; a humidifier configured to provide water vapor tohumidify the supply of pressurized breathable air; a water reservoirincluding a cavity structured to hold a volume of water, the waterreservoir including a heat conductive portion; a water reservoir dockincluding a cavity structured and arranged to receive the waterreservoir in an operative position, the water reservoir dock including aheating assembly adapted to thermally engage the heat conductive portionof the water reservoir in the operative position to allow thermaltransfer of heat from the heating assembly to the volume of water; andan alignment arrangement including at least one protrusion protrudingoutwardly from a side of the water reservoir and at least one slot on aside of the water reservoir dock, the at least one slot configured tofully receive the at least one protrusion upon complete insertion of thewater reservoir into the water reservoir dock to a maximum possibleextent, wherein the at least one protrusion only extends partially alongthe side of the water reservoir, and the at least one slot only extendspartially along the side of the water reservoir dock, wherein the waterreservoir includes an insertion end and a graspable end that is oppositeto the insertion end, wherein the insertion end is configured to beinserted into the cavity of the water reservoir dock and at least aportion of the graspable end remains graspable by the patient when thewater reservoir is inserted into the cavity of the water reservoir dockto the maximum possible extent, wherein the at least one protrusionforms an extension of the graspable end, wherein at least part of the atleast one protrusion tapers down towards the insertion end, and whereinthe at least one protrusion includes a leading end that is spacedrearward from a leading edge on the insertion end of the waterreservoir.
 43. The medical treatment apparatus according to claim 42,wherein the water reservoir further includes a pair of upwardly orientedand spaced apart surfaces provided to the leading edge of the waterreservoir configured to engage underneath a respective one of a pair ofspaced apart abutment edges provided to a rear wall of the waterreservoir dock when the water reservoir reaches the operative position,and wherein the pair of upwardly oriented and spaced part surfaces isconfigured to engage and be forced downwardly by the pair of spaced partabutment edges to enhance engagement of the heat conductive portion withthe heating assembly.
 44. The medical treatment apparatus according toclaim 42, wherein the at least one protrusion is one of a pair of guiderails and the at least one slot is one of a pair of guide slots, each ofthe guide rails including an upper edge providing an upwardly orientedsurface, and each of the guide slots includes an upper edge providing adownwardly oriented surface, and wherein the upwardly oriented surfaceof each of the guide rails is configured to engage and be forceddownwardly by the downwardly oriented surface of a respective one of theguide slots to enhance engagement of the heat conductive portion withthe heating assembly.
 45. The medical treatment apparatus according toclaim 44, wherein each of the guide rails includes one or moreengagement tabs extending from the upwardly oriented surface so as toengage with the upper edge of a respective one of the guide slots. 46.The medical treatment apparatus according to claim 42, wherein the waterreservoir includes a transitional shoulder formed along a top and a sideof the water reservoir, wherein the transitional shoulder is formedbetween the insertion end and the graspable end, wherein the at leastone protrusion has a trailing end positioned to extend from thetransitional shoulder towards the insertion end, wherein the leading endof the at least one protrusion terminates at a central portion of thewater reservoir.
 47. The medical treatment apparatus according to claim46, wherein the heat conductive portion of the water reservoir spans atleast part of the insertion end and at least part of the graspable end,the heat conductive portion including a leading end formed on theinsertion end and a trailing end formed on the graspable end, and, whenvertically projected downwards, the at least one protrusion ispositioned between the leading end and the trailing end of the heatconductive portion.
 48. The medical treatment apparatus according toclaim 47, wherein the trailing end of the at least one protrusion ishorizontally offset from the trailing end of the heat conductiveportion, and the leading end of the at least one protrusion ispositioned closer to the leading edge of the insertion end as comparedto the trailing end of the heat conductive portion.
 49. The medicaltreatment apparatus according to claim 46, wherein the top of the waterreservoir includes a second shoulder spaced further towards the leadingedge of the insertion end compared to the transitional shoulder, andwherein a first horizontal distance between the transitional shoulderand the second shoulder is greater than a second horizontal distancebetween the transitional shoulder and the leading end of the at leastone protrusion.
 50. The medical treatment apparatus according to claim46, wherein the trailing end of the at least one protrusion iscompletely inserted into the at least one slot when (1) an inlet and/oroutlet opening of the water reservoir engages a seal suspended withinthe cavity of the water reservoir dock and (2) the transitional shoulderof the water reservoir engages a front edge of the cavity of the waterreservoir dock.
 51. The medical treatment apparatus according to claim42, wherein the leading end of the at least one protrusion is insertedinto the at least one slot only after the water reservoir has beenpartially inserted into the cavity of the water reservoir dock.
 52. Themedical treatment apparatus according to claim 42, wherein the waterreservoir comprises a reservoir base and a reservoir lid pivotallycoupled to the reservoir base, and wherein the at least one protrusionextends in a horizontal direction and is positioned at a height that isvertically aligned with a pivot axis about which the reservoir lidpivots relative to the reservoir base.
 53. The medical treatmentapparatus according to claim 42, wherein the water reservoir comprises areservoir lid having a retainer that is releasably engaged with a recessin an upper, inside wall of the water reservoir dock in the operativeposition, and wherein the retainer is vertically aligned with the atleast one protrusion.
 54. The medical treatment apparatus according toclaim 42, further comprising one or more engagement tabs on each side ofthe water reservoir, each of the one or more engagement tabs configuredto be forced downwardly by the water reservoir dock to enhanceengagement of the heat conductive portion with the heating assembly. 55.The medical treatment apparatus according to claim 54, wherein the waterreservoir comprises a reservoir lid having a retainer that is releasablyengaged with a recess in the water reservoir dock in the operativeposition, and one of the engagement tabs is substantially aligned withthe retainer in a vertical plane, as seen from side view.
 56. Themedical treatment apparatus according to claim 54, wherein one of theengagement tabs engages with the water reservoir dock before the atleast one protrusion is completely inserted into the at least one slot.57. The medical treatment apparatus according to claim 42, wherein theat least one slot is open ended from the side so that the at least oneprotrusion is visible through the at least one slot when the waterreservoir is in the operative position.
 58. The medical treatmentapparatus according to claim 42, wherein the water reservoir comprises areservoir base, a reservoir lid, and a hinge joint to hingedly couplethe reservoir lid to the reservoir base for hinged movement between anopen position and a closed position.
 59. The medical treatment apparatusaccording to claim 58, further comprising a latch arrangement toreleasably retain the reservoir lid to the reservoir base in the closedposition, wherein the hinge joint is positioned on the insertion end ofthe water reservoir and the latch arrangement is positioned on theopposite, graspable end of the water reservoir.
 60. The medicaltreatment apparatus according to claim 58, wherein the reservoir lid andthe reservoir base are configured to join at a seam in the closedposition, and the at least one protrusion is arranged below the seam.61. The medical treatment apparatus according to claim 60, furthercomprising a seal provided to the reservoir lid, the seal configured tosealingly engage the reservoir lid and the reservoir base along the seamwhen the water reservoir is in the closed position.
 62. The medicaltreatment apparatus according to claim 58, wherein the at least oneprotrusion is formed on the reservoir base independent of the reservoirlid.
 63. The medical treatment apparatus according to claim 42, whereinthe at least one protrusion includes a first width proximate thegraspable end and a second width proximate the insertion end, the firstwidth is greater than the second width.
 64. The medical treatmentapparatus according to claim 63, wherein the graspable end comprises aprotrusion adjacent the first width of the at least one protrusion, andthe protrusion of the graspable end at least partly forms a stop to atleast partly limit insertion depth of the water reservoir into thecavity of the water reservoir dock.
 65. The medical treatment apparatusaccording to claim 42, wherein the at least one protrusion is fullyreceived within the at least one slot when the water reservoir is in theoperative position such that engagement of the leading end of the atleast one protrusion with the at least one slot at least partly forms astop to at least partly limit insertion depth of the water reservoirinto the cavity of the water reservoir dock.
 66. The medical treatmentapparatus according to claim 42, wherein the water reservoir isengagable with the water reservoir dock by horizontal sliding.
 67. Themedical treatment apparatus according to claim 43, wherein each of thepair of upwardly oriented and spaced apart surfaces extends in a planethat is offset with respect to adjacent surfaces at the leading edge ofthe water reservoir.
 68. The medical treatment apparatus according toclaim 43, wherein each of the pair of upwardly oriented and spaced apartsurfaces includes a height from the heat conductive portion that issimilar to a height of an upwardly oriented surface of the at least oneprotrusion from the heat conductive portion.
 69. The medical treatmentapparatus according to claim 42, wherein the water reservoir furtherincludes a pair of upwardly oriented and spaced apart surfaces providedto the leading edge of the water reservoir configured to engageunderneath a respective one of a pair of spaced apart abutment edgesprovided to a rear wall of the water reservoir dock when the waterreservoir reaches the operative position, and wherein the pair ofupwardly oriented and spaced part surfaces is configured to engage andbe forced downwardly by the pair of spaced part abutment edges toenhance engagement of the heat conductive portion with the heatingassembly, wherein the at least one protrusion is one of a pair of guiderails and the at least one slot is one of a pair of guide slots, each ofthe guide rails including an upper edge providing an upwardly orientedsurface, and each of the guide slots includes an upper edge providing adownwardly oriented surface, and wherein the upwardly oriented surfaceof each of the guide rails is configured to engage and be forceddownwardly by the downwardly oriented surface of a respective one of theguide slots to enhance engagement of the heat conductive portion withthe heating assembly wherein each of the guide rails includes one ormore engagement tabs extending from the upwardly oriented surface so asto engage with the upper edge of a respective one of the guide slotswherein the water reservoir comprises a reservoir base, a reservoir lid,and a hinge joint to hingedly couple the reservoir lid to the reservoirbase for hinged movement between an open position and a closed position,further comprising a latch arrangement to releasably retain thereservoir lid to the reservoir base in the closed position, wherein thehinge joint is positioned on the insertion end of the water reservoirand the latch arrangement is positioned on the opposite, graspable endof the water reservoir, wherein the reservoir lid and the reservoir baseare configured to join at a seam in the closed position, and the atleast one protrusion is arranged below the seam, further comprising aseal provided to the reservoir lid, the seal configured to sealinglyengage the reservoir lid and the reservoir base along the seam when thewater reservoir is in the closed position, wherein the at least oneprotrusion is formed on the reservoir base independent of the reservoirlid, wherein the at least one protrusion includes a first widthproximate the graspable end and a second width proximate the insertionend, the first width is greater than the second width, wherein thegraspable end comprises a protrusion adjacent the first width of the atleast one protrusion, and the protrusion of the graspable end at leastpartly forms a stop to at least partly limit insertion depth of thewater reservoir into the cavity of the water reservoir dock, wherein theat least one protrusion is fully received within the at least one slotwhen the water reservoir is in the operative position such thatengagement of the leading end of the at least one protrusion with the atleast one slot at least partly forms a stop to at least partly limitinsertion depth of the water reservoir into the cavity of the waterreservoir dock, wherein the heat conductive portion of the waterreservoir includes a leading end proximate the insertion end and atrailing end proximate the graspable end, and the at least oneprotrusion is arranged between the leading end and the trailing end ofthe heat conductive portion, wherein the water reservoir is engagablewith the water reservoir dock by horizontal sliding, wherein each of thepair of said upwardly oriented and spaced apart surfaces extends in aplane that is offset with respect to adjacent surfaces at the leadingedge of the water reservoir, and wherein each of the pair of upwardlyoriented and spaced apart surfaces includes a height from the heatconductive portion that is similar to a height of an upwardly orientedsurface of the at least one protrusion from the heat conductive portion.70. The medical treatment apparatus according to claim 42, wherein thewater reservoir comprises a reservoir base, a reservoir lid, and a hingejoint to hingedly couple the reservoir lid to the reservoir base forhinged movement between an open position and a closed position, furthercomprising a latch arrangement to releasably retain the reservoir lid tothe reservoir base in the closed position, wherein the hinge joint ispositioned on the insertion end of the water reservoir and the latcharrangement is positioned on the opposite, graspable end of the waterreservoir, wherein the reservoir lid and the reservoir base areconfigured to join at a seam in the closed position, and the at leastone protrusion is arranged below the seam, further comprising a sealprovided to the reservoir lid, the seal configured to sealingly engagethe reservoir lid and the reservoir base along the seam when the waterreservoir is in the closed position, wherein the at least one protrusionis formed on the reservoir base independent of the reservoir lid,wherein the at least one protrusion includes a first width proximate thegraspable end and a second width proximate the insertion end, the firstwidth is greater than the second width, wherein the graspable endcomprises a protrusion adjacent the first width of the at least oneprotrusion, and the protrusion of the graspable end at least partlyforms a stop to at least partly limit insertion depth of the waterreservoir into the cavity of the water reservoir dock, wherein the waterreservoir is engagable with the water reservoir dock by horizontalsliding, wherein the water reservoir includes a transitional shoulderformed along a top and a side of the water reservoir, wherein thetransitional shoulder is formed between the insertion end and thegraspable end, wherein the at least one protrusion has a trailing endpositioned to extend from the transitional shoulder towards theinsertion end, wherein the leading end of the at least one protrusionterminates at a central portion of the water reservoir, wherein the heatconductive portion of the water reservoir spans at least part of theinsertion end and at least part of the graspable end, the heatconductive portion including a leading end formed on the insertion endand a trailing end formed on the graspable end, and when verticallyprojected downwards, the at least one protrusion is positioned betweenthe leading end and the trailing end of the heat conductive portion,wherein the trailing end of the at least one protrusion is horizontallyoffset from the trailing end of the heat conductive portion, and thetrailing end of the at least one protrusion is positioned closer to theleading edge of the insertion end as compared to the trailing end of theheat conductive portion, wherein the top of the water reservoir includesa second shoulder spaced further towards the leading edge of theinsertion end compared to the transitional shoulder, and wherein a firsthorizontal distance between the transitional shoulder and the secondshoulder is greater than a second horizontal distance between thetransitional shoulder and the leading end of the at least oneprotrusion, wherein the trailing end of the at least one protrusion iscompletely inserted into the at least one slot when (1) an inlet and/oroutlet opening of the water reservoir engages a seal suspended withinthe cavity of the water reservoir dock and (2) the transitional shoulderof the water reservoir engages a front edge of the cavity of the waterreservoir dock, wherein the leading end of the at least one protrusionis inserted into the at least one slot only after the water reservoirhas been partially inserted into the cavity of the water reservoir dock,wherein the at least one protrusion extends in a horizontal directionand is positioned at a height that is vertically aligned with a pivotaxis about which the reservoir lid pivots relative to the reservoirbase, wherein the a reservoir lid has a retainer that is releasablyengaged with a recess in an upper, inside wall of the water reservoirdock in the operative position, and wherein the retainer is verticallyaligned with the at least one protrusion, further comprising one or moreengagement tabs on each side of the water reservoir, each of the one ormore engagement tabs configured to be forced downwardly by the waterreservoir dock to enhance engagement of the heat conductive portion withthe heating assembly, wherein one of the engagement tabs issubstantially aligned with the retainer in a vertical plane, as seenfrom side view, and wherein one of the engagement tabs engages with thewater reservoir dock before the at least one protrusion is completelyinserted into the at least one slot.